I noticed there is a lot of articles that is specified an incorrect images path that only works in IE , those articles used the backslash ("\") character in the Images paths , note that using backslash in the images URL is incorrect ! instead we must use the slash ("/") , for example
this image will not be recognized by Firefox :
<img src='\images\left.gif' ....
instead it must be
<img src='/images/left.gif' ....
what about asp:Image ?
if you used the backslash in the asp image control , the run time will change it to slash if and only if you used a relative image path , for example
<asp:Image ID="Image1" runat="server" ImageUrl="~\images\left.gif" />
will be rendered as
<img id="Image1" src="images/left.gif" style="border-width:0px;" />
Of course the same rule applies when specifying the image URL in the style sheets , for example when settings the Background-image attribute ,
background-image:url(images/left.gif);
Hope it Helps
Anas Ghanem