We're using Squid 3.0STABLE18 (just upgraded to see if it would fix this problem - it did not). We have a website our uses have to go to - http://mprisk.org On the bottom right of the page, there's a "Quicklinks" that calls the following URL in a iFrame. If the request goes through Squid, it doesn't display (IE 7/8, FF3.5). If you call the URL directly without Squid, it displays fine. No errors in the Squid log. http://mprisk.org/MPR_Content/absolutecr.aspx?z=18&isframe=1 Any ideas? Thanks!