Hello all,
I am despertly trying to center my header image on my site; http://cultofgreg.us

I have successfully centered it in Firefox, but when accessing the site through Chrome it initially is offset. But if I refresh the page or downsize it, the header snaps back to the center.

I believe this is because Firefox places the far left edge of the image in the center and Chrome places the center in the center. So in Firefox I must put a negative margin on the image to have it stay centered. Chrome then reads this negative margin and offsets the image to the left. But like I said earlier, if I refresh the page the image is put back into the center.

I have no idea what's going on. The code is as follows. Any help or information to help me understand why its doing this will be greatly appreciated. Thank you so much. II'm going a little crazy)

Code:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<title>{Title}{block:PostTitle} - {PostTitle}{/block:PostTitle}</title>
{block:Description}
<meta name="Description" content="{MetaDescription}" />
{/block:Description}
<link rel="shortcut icon" href="{favicon}" />

<meta name="color:background" content="#FEFEFE" />
<meta name="color:border" content="#EEEEEE" />
<meta name="color:info" content="#666666" />
<meta name="color:info border" content="#EEEEEE" />
<meta name="color:info link" content="#AAAAAA" />
<meta name="color:info link hover" content="#EEEEEE" />
<meta name="color:links" content="#BBBBBB" />
<meta name="color:links bg" content="#FAFAFA" />
<meta name="color:links hover" content="#444444" />
<meta name="color:menu link" content="#AAAAAA" />
<meta name="color:menu link bg" content="#FAFAFA" />
<meta name="color:menu link hover" content="#FFFFFF" />
<meta name="color:menu link hover bg" content="#444444" />
<meta name="color:permalink" content="#666666" />
<meta name="color:permalink hover" content="#BBBBBB" />
<meta name="color:pagination" content="#AAAAAA" />
<meta name="color:pagination hover" content="#444444" />
<meta name="color:post" content="#888888" />
<meta name="color:post bg" content="#FFFFFF" />
<meta name="color:post border" content="#EEEEEE" />
<meta name="color:post title" content="#666666" />
<meta name="color:post title border" content="#EEEEEE" />
<meta name="image:Header" content="" />
<meta name="image:background" content="">
<meta name="if:fade effect" content="1" />
<meta name="if:hover effects" content="1" />
<meta name="if:show captions" content="1" />
<meta name="if:show tags" content="0" />



<style type="text/css">
body {padding:0px;margin-top:60px!important;margin:5px;background:{color:background} url({image:background}) fixed;border-top:1px dotted {color:border};}
.tumblrAutoPager_page_info, .tumblrAutoPager_page_separator {display:none;}
:hover {-webkit-transition: all 0.5s ease;-moz-transition: all 0.5s ease;-o-transition: all 0.5s ease;}
#infscr-loading {display:none;}
iframe#tumblr_controls {right:3px !important; position: fixed !important;opacity: 0.2;filter:alpha(opacity=20);-moz-opacity: 0.2;-khtml-opacity: 0.2;-webkit-transition: all 0.9s ease;-moz-transition: all 0.9s ease;-o-transition: all 0.9s ease;}
iframe#tumblr_controls:hover{opacity: 1;filter:alpha(opacity=100);-moz-opacity: 1;-khtml-opacity: 1;-webkit-transition: all 0.9s ease;-moz-transition: all 0.9s ease;-o-transition: all 0.9s ease;}
a {text-decoration:none;-webkit-transition: all 0.5s ease;-moz-transition: all 0.5s ease;-o-transition: all 0.5s ease;}

#header {height:109px; margin-left:-180px; position:fixed; top:10px; z-index:10;} 

#menuP {position:fixed;right:10px;top:58px;z-index:11;}
#menuV {position:fixed;left:10px;top:54px;z-index:12;}

#border-top {background:{color:background};border-bottom:1px dotted {color:border};margin:0px;z-index:9;height:90px;position:fixed;top:0px;left:0px;border-right:5px solid {color:background};border-left:5px solid {color:background};width:100%;}

#entry {margin-top:50px!important;margin:0px auto; font:13px/12px trebuchet ms, lucida sans unicode, sans-serif;overflow:hidden;padding:0px;{block:IndexPage}width:892px!important;{/block:IndexPage}{block:PermalinkPage}width:892px!important;{/block:PermalinkPage}}
#wrap {margin-bottom:30px!important;{block:indexpage}border-top:1px dotted {color:post border};{/block:indexpage}overflow:visible;margin-top:30px!important;}

#post {background:{color:post bg};padding:10px!important;{block:IndexPage}width:800px!important;{/block:IndexPage}{block:PermalinkPage}width:800px!important;{/block:PermalinkPage}margin-left:70px;border:1px dotted {color:post border};margin-top:-10px;overflow:hidden;}

#note {background:{color:post bg};padding:10px!important;
{block:IndexPage}width:800px!important;{/block:IndexPage}{block:PermalinkPage}width:800px!important;{/block:PermalinkPage};
margin-left:70px;border:1px dotted {color:post border};margin-top:10px!Important;}

div.caption img, #text img {{block:IndexPage}width:600px!important;{/block:IndexPage}{block:PermalinkPage}width:600px!important;{/block:PermalinkPage}}

div.video embed, div.post div.video object, div.video iframe, #video {{block:IndexPage}width:800px; height:600px; {/block:IndexPage} {block:PermalinkPage}width:800px; height:600px; {/block:PermalinkPage}}

#info {float:left;width:40px;background:{color:post bg};padding:5px 10px;text-align:center;border:1px dotted {color:post border};margin-top:-10px!Important;font:8px trebuchet ms, lucida sans unicode, sans-serif;text-transform:uppercase;letter-spacing:2px;{block:permalinkpage}visibility:hidden{/block:permalinkpage}}
#info a {color:{color:permalink};}
h1, h1 a {font:italic 16px/10px garamond, georgia, times new roman, serif!important;color:{color:post title}!important;margin:0px;margin-bottom:15px!important;letter-spacing:1px!important;text-align:center;text-decoration:none!important;background:none!important;}
h1 a{border-bottom:1px dotted {color:post title border};}
blockquote {margin:5px 10px;padding:0px 5px;border-left:1px dotted {color:info border};}
blockquote p{margin:3px 0px;padding:0px;}
#text, .caption {color:{color:post};}
#tags {margin:0px;display:block;font:7px trebuchet ms, lucida sans unicode, sans-serif;color:{color:info};text-transform:uppercase;letter-spacing:2px;border-top:1px dotted {color:info border};padding-top:7px;margin-top:9px!important;}
#tags a{color:{color:info link}!important;font:italic 11px/8px garamond, georgia, times new roman, serif!important;text-transform:none!important;letter-spacing:1px!important;text-decoration:none!important;}
div.caption a, #text a {font:italic 11px/11px garamond, georgia, times new roman, serif;color:{color:links};letter-spacing:1px;background:{color:links bg};text-decoration:none;padding:0 3px;}
#quote, #asked, #asker a {font:italic 14px/12px garamond, georgia, times new roman, serif;letter-spacing:1px;background:none!important;border-bottom:none!Important;} 
#asker {margin-bottom:3px;border-bottom:1px dotted {color:info border};}
#quotesource {text-align:right;padding-top:5px;}
#album{float:left;margin:0px 7px;}
#audio {min-height:105px;}
#player {width:28px;height:32px;overflow:hidden;position:absolute;margin-left:45px;margin-top:43px;}
ol.notes {padding: 0px;margin: 0px;list-style-type: none;text-transform:uppercase;font-size:7px!Important;letter-spacing:1px;}
ol.notes li.note img.avatar {border:1px dotted {color:info border};margin-bottom:5px;vertical-align: -15px;padding:4px;}
#note a{color:{color:info link};}
#page {width:100%;position:fixed;top:200px;z-index:20;}
#page a{font:100px trebuchet ms, lucida sans unicode, sans-serif;color:{color:pagination};margin:5px;}
#prev {float:left;}
#next {float:right;}
{block:iffadeeffect}
img {opacity:0.7;-webkit-transition: opacity 0.5s linear;-webkit-transition: all 0.5s ease-in-out;-moz-transition: all 0.5s ease-in-out;-o-transition: all 0.5s ease-in-out;}
img:hover {opacity:1;}{/block:iffadeeffect}
{block:ifhovereffects}
#page a:hover {color:{color:pagination hover};}
#note a:hover {color:{color:info link hover}!important;}
div.caption a:hover, #text a:hover {letter-spacing:2px;text-decoration:line-through;color:{color:links hover};background:none!important;}
h1 a:hover {letter-spacing:1px!important;text-decoration:none!important;color:{color:links hover}!important;}
#asker a:hover {letter-spacing:1px!important;text-decoration:none!important;color:{color:links hover}!important;}
#info a:hover {color:{color:permalink hover}!important;}
#tags a:hover {color:{color:info link hover}!important;}
{/block:ifhovereffects}
</style>

<script type="text/javascript">

  var _gaq = _gaq || [];
  _gaq.push(['_setAccount', 'UA-24446664-1']);
  _gaq.push(['_trackPageview']);

  (function() {
    var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
    ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
    var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
  })();

</script>

<script type="text/javascript" src="http://static.extension.fm/exfm.js?bg_color=fa0505&display_color=fa0505&playlist_top_color=fa0505&font_color=e6e7ff"></script>

</head>
<body>

<center>
<a href="/"><img id="header" src="{image:Header}" title="Home"> </a>
</center>


<div id="page">
     {block:Pagination}
 
 {block:PreviousPage}
 <div id="prev"><a href="{PreviousPage}">&laquo</a></div>
 {/block:PreviousPage}
 
 {block:NextPage}
 <div id="next"><a href="{NextPage}">&raquo;</a></div>
 {/block:NextPage}
 {/block:Pagination}
 </div>
 
<div id="border-top"></div>



<div id="menuV">
        <a href="/musicvideo"><img src="http://static.tumblr.com/76qeeol/gcum9wnrc/tv.png" title="VIDEOS"></a>
    </div>    
<div id="menuP">        
          <a href="/superzoom"><img src="http://static.tumblr.com/76qeeol/MAUm9wodl/camera.png" title="PICTURES"></a>
</div>

<div id="entry">
{block:Posts}
<div id="wrap">

{block:IndexPage}<div id="info"><a href="{Permalink}"> {ShortMonth} {DayofMonthwithZero}</br> {Year}</a></div>{/block:IndexPage}

<div id="post">

{block:Text}<div id="text">{block:Title}<h1>{Title}</h1>{/block:Title}{Body}</div>{/block:Text}

{block:Photo}
        {block:indexpage}<div id="border"><a href="/"><img src="{PhotoURL-500}" border="0"/></a></div>{/block:indexpage}
        {block:ifshowcaptions}{block:indexpage}{block:caption}<div class="caption">{caption}</div>{/block:caption}{/block:indexpage}{/block:ifshowcaptions}
        {block:permalinkpage}<div id="border">{LinkOpenTag}<img src="{PhotoURL-500}"/>{LinkCloseTag}</div>{block:caption}<div class="caption">{caption}</div>{/block:caption}{/block:permalinkpage}
{/block:Photo}

{block:Photoset}
        {block:indexpage}<div id="border">{Photoset-500}</div>{/block:indexpage}
        {block:ifshowcaptions}{block:indexpage}{block:caption}<div class="caption">{caption}</div>{/block:caption}{/block:indexpage}{/block:ifshowcaptions}
        {block:permalinkpage}<div id="border">{Photoset-500}</div>{block:caption}<div class="caption">{caption}</div>{/block:caption}{/block:permalinkpage}
{/block:Photoset}
 
{block:Quote}<div id="text">
        <div id="quote">{Quote}</div>
        {block:Source}<div id="quotesource">{Source}</div>{/block:Source}</div>
{/block:Quote}
 
{block:Link}<div id="text">
        <h1><a href="{URL}" target="{Target}">{Name}</a></h1>
        {block:Description}{Description}{/block:Description}</div>
{/block:Link}
 
{block:Chat}<div id="text">
        {block:Title}<h1>{Title}</h1>{/block:Title}
        {block:Lines}{block:Label}<b><i>{Label}</i></b>{/block:Label} {Line}<br>{/block:Lines}</div>
{/block:Chat}
 
{block:Audio}<div id="text">
        <div id="audio"> <div id="player">{AudioPlayerWhite} </div>      
{block:ifshowcaptions}<div id="album">{block:AlbumArt}<img src="{AlbumArtURL}" width="100">{/block:AlbumArt}</div>
{PlayCountWithLabel} {block:caption}<div class="caption">{caption}</div>{/block:caption}{/block:ifshowcaptions}
</div>
</div>
{/block:Audio}

{block:Video}
<div class="entry">
<div class="video">{Video-500}
{block:ifshowcaptions}{block:IndexPage}{block:Caption}<div class="caption" style="background:{color:captions bg};">{caption}</div>{/block:Caption}{/block:IndexPage}{/block:ifshowcaptions}</div>
{block:permalinkpage}{block:caption}<div class="caption">{caption}</div>{/block:caption}{/block:permalinkpage}
{/block:Video}
 
{block:Answer}<div id="text" style="min-height:50px;">
        <div id="asker"><img src="{AskerPortraitURL-30}" style="margin-top:0px!important;margin:5px;float:left;border:1px dotted {color:info border};padding:5px;background:{color:post bg};"> {Asker} <font id="asked">asked:</font> {Question}</div>
        <p style="margin-left:5px;">{Answer}</p></div>
{/block:Answer}


{block:ifshowtags}
{block:indexpage}{block:HasTags}<span id="tags">tagged: {block:Tags}<a href="{TagURL}">{Tag}</a> - {/block:Tags}</span>{/block:HasTags}{/block:indexpage}{/block:ifshowtags}

{block:permalinkpage}
<span id="tags">
{block:Date} {Month} {DayofMonth}, {Year}{/block:Date} {block:NoteCount} with {NoteCountWithLabel} {/block:NoteCount}

{block:HasTags}<br>tagged: {block:Tags}<a href="{TagURL}">{Tag}</a> - {/block:Tags}{/block:HasTags}

</span>
{/block:permalinkpage}

</div>
    {block:PermalinkPage}
        {block:PostNotes}
                <div id="note">{PostNotes}</div>
        {/block:PostNotes}
{/block:permalinkpage}
</div>
{/block:Posts}
</div>

</body>
</html>