IE-b0rker returns
Now complete with large annoying red border. Here's a screenshot of Opera pretending to be IE.
I'm using this code to detect IE browsers:
<?php if(strstr($_SERVER['HTTP_USER_AGENT'],"MSIE")) { ?>
If anyone knows a better way, I'd love to hear it.

If you want the red border to be displayed only in IE use conditional comments (http://www.quirksmode.org/css/condcom.html).
For example in the stylesheet for all user agents there may be line:
#redframe {display:none}And in the stylesheet included like this:
You may put line:
#redframe {display:block}… Your wordpress delete my code ;p
It must look like this:
<!--[if IE 6]>
<link rel=”stylesheet” src=”ss_for_ie_only.css” />
<![endif]-->
Maybe now it will work ;)
IE-specific code makes me cry. But that looks useful if I ever want to mangle a page in IE again, thanks. :)