We ran into an interesting issue with IE, we aggregate CSS at build time per JSP file and recently we introduced Jquery and colorbox into the current release that caused the css size to grow beyond 300K. Everything would work find locally as we dont do aggregation in development mode but things wont work in QA environment on IE, Firefox would work fine. Some of the images wont show up in IE no matter what you do and one of the developer found that IE will ignore any css beyond 288 KB and even gzipping content doesn't matter because its the final size the IE will have to parse that matters. Fortunately the solution was to just create two aggregate css instead of one and that solved the issue. More details on this are at http://joshua.perina.com/africa/gambia/fajara/post/internet-explorer-css-file-size-limit