Why doesn't my site work in IE6 or IE7?

Question

For some reason my site displays a "Cannot display this message" error in those browsers while working correctly in Firefox, Opera, Safari and IE8.

It looks like this: http://www.reviewsaurus.com/images/pagedisplay.png

This document was successfully checked as XHTML 1.0 Transitional!

Answer 1

This document was successfully checked as XHTML 1.0 Transitional!

It still doesn't work though...

Found the problem:

Was using the following procedures to remove unnecessary characters, seems to be wrong though.

<?php   
function callback($buffer) 
{ 
    $holdit=$buffer;
    $holdit=str_replace("   ", " ", $holdit); // tab
    $holdit=str_replace("  ", " ", $holdit); // double space
    $holdit=str_replace("\n", " ", $holdit); // new line
    $holdit=str_replace("\r", " ", $holdit); // new line
    $holdit = eregi_replace("<!--[^>]*-->"," ",$holdit); // comment
    return $holdit; 
}
ob_start("ob_gzhandler"); 
ob_start("callback");
?>

Seems I don't need that function either, it is faster without it.
(I should probably have opted for a single eregi_replace too)