Changing images and map on mouseover not working as expected with IE

I have a problem when changing images and image maps with mouseover and click events in IE. Firefox, Chrome and Safari all work well but IE does not. It's hard to describe but when I mouse over a hot spot the image changes and then right away changes back. you can see it here (http://www.deadlinesolutions.com/index.php/services-mainmenu-28/deltav#): here is the Javascript code:

var current_overID = "";
var last_overID = "";

function item (img_name,width,height)
{
img_prefix = img_name;
this.slide_img = new Image (width,height);
this.slide_img.src = "http://www.dsisyr.com/images/stories/DeltaV/" + img_prefix + ".jpg";
}

function new_item (img_name,width,height)
{
item [img_name] = new item (img_name,width,height);
}

function mouseover (itemID, mapID)
{
current_overID = itemID;
if (current_overID != last_overID) {
document.deltavmap.src = item [current_overID].slide_img.src;
document.deltavmap.useMap=mapID;
}
}


new_item ("DSI-DeltaV1",700,300);
new_item ("DSI-DeltaV1-2-1",700,300);
new_item ("DSI-DeltaV1-2-2",700,300);
.....many more


<MAP NAME="deltav">
<AREA SHAPE="RECT" COORDS="27,27,219,53" HREF="#" Onmouseover="mouseover('DSI-DeltaV1-2-1', '#eng')" window.defaultStatus='' window.status='Engineering' return true >
<AREA SHAPE="RECT" COORDS="27,74,171,97" HREF="#" Onmouseover="mouseover('DSI-DeltaV1-3-1', '#sw')" window.defaultStatus='' window.status='Software'; return true >
<AREA SHAPE="RECT" COORDS="27,122,270,145" HREF="#" Onmouseover="mouseover('DSI-DeltaV1-4-1', '#doc')" window.defaultStatus='' window.status='Documentation'; return true >
<AREA SHAPE="RECT" COORDS="27,167,156,195" HREF="#" Onmouseover="mouseover('DSI-DeltaV1-5-1', '#sup')" window.defaultStatus='' window.status='Support'; return true >
<AREA SHAPE="DEFAULT" NOHREF>

</MAP>

<MAP NAME="eng">
<AREA SHAPE="RECT" COORDS="38,52,244,75"
HREF="#" Onmouseover="mouseover('DSI-DeltaV1-2-1', '#eng') "
window.defaultStatus=''
window.status='Batch Processing' return true
>
<AREA SHAPE="RECT" COORDS="40,82,230,103"
HREF="#" Onmouseover="mouseover('DSI-DeltaV1-2-2', '#eng')"
window.defaultStatus=''
window.status='Control Modules' return true
>
<AREA SHAPE="RECT" COORDS="40,112,143,136"
HREF="#" Onmouseover="mouseover('DSI-DeltaV1-2-3', '#eng')"
window.defaultStatus=''
window.status='Graphics' return true
>
<AREA SHAPE="RECT" COORDS="40,141,176,168"
HREF="#" Onmouseover="mouseover('DSI-DeltaV1-2-4', '#eng')"
window.defaultStatus=''
window.status='ProtoTyping' return true
>
<AREA SHAPE="RECT" COORDS="24,224,84,234"
HREF="#" OnClick="mouseover('DSI-DeltaV1-3-1', '#sw')"
window.defaultStatus=''
window.status='Software' return true
>
<AREA SHAPE="RECT" COORDS="24,236,124,247"
HREF="#" OnClick="mouseover('DSI-DeltaV1-4-1', '#doc')"
window.defaultStatus=''
window.status='Documentation' return true
>
<AREA SHAPE="RECT" COORDS="25,248,76,261"
HREF="#" OnClick="mouseover('DSI-DeltaV1-5-1', '#sup')"
window.defaultStatus=''
window.status='Support' return true
>
<AREA SHAPE="RECT" COORDS="620,240,699,399" HREF="#" OnClick="mouseover('DSI-DeltaV1', '#deltav')" window.defaultStatus='' window.status='deltav'; return true >
<AREA SHAPE="DEFAULT" NOHREF>

</MAP>
... many others
Can any one tell me what i need to do to fix this in IE? Thanks!
Fayette

I don't understand this part

Onmouseover="mouseover('DSI-DeltaV1-2-1', '#eng')" window.defaultStatus='' window.status='Engineering' return true


First of all, it's onmouseover instead of Onmouseover ...

Second, the attribute onmouseover ends with the second double quote ... but there is more javascript after that, without any semicolons ... what is supposed to happen there? This is clearly not correct syntactically.

Thanks for the input. This is my first javascript. I got the code from a tutorial i found online and adapted it for my needs. that is how they had the code. Guess i'll not go there again :).

I took out the part to the right of the quotes ( window.defaultStatus='' window.status='Engineering' return true) and used DreamWeaver to give me the caps on onMouseOver and onClcick. As I understand it the code you quoted is in the map which is not javascript. It did not change the functionality at all. anymore Ideas?
Thanks!