header backgrounds...

This code I've seen used in many places, and I've used it myself a few times but its just not working in FF atm. In IE everything is fine.

This is the css


#thirdleft h1{
background-image:url(../images/eventsh.gif);
background-position: 3px 3px;
background-repeat:no-repeat;
width:48px;
height:15px;
margin:0px;
}
#thirdleft h1 span{
display:none;}


html:
<div id = "thirdbar"><div id = "thirdleft">
<img src="images/dancing.jpg" width="159" height="120" alt = "teens breakdancing" align = "left" />
<h1><span>Events</span></h1>
</div>
</div>

Why even put the span in there? What part isn't working? Is it not showing the image? Do you have a link to the site? Are you sure you used the proper notation for going back directories?