User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.8) Gecko/20050602 Firefox/1.0.4 Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.8) Gecko/20050602 Firefox/1.0.4 Firefox uses 98% CPU on both Windows 2000 and on Linux when visiting crca.co.uk. The page is a frameset. The individual frames do not cause the problem when loaded on their own. When the frameset is loaded, all the side frames and most of the main frame loads before the freeze. However, if the individual frames are visited first (so they are in cache), then the main page is visited, the page freezes firefox immediately. Reproducible: Always Steps to Reproduce: 1. Visit crca.co.uk Actual Results: Firefox UI becomes unresponsive after loading all side frames and most of the main frame. top (Linux) and task manager (Windows) show around 98% CPU usage for Firefox Expected Results: Shown the site as normal. Occurs with default theme and without plugins installed (tested on Windows computer) and with Qute theme with several plugins installed (Linux computer). Two different hardware configurations.

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b3) Gecko/20050711 Firefox/1.0+ ID:2005071106 Visiting the URL causes firefox to become very unresponsive so this problem is still present in trunk builds.

It's because of this function: function monitorScroll(){ which calls setInterval(monitorScroll,0); *** This bug has been marked as a duplicate of 261633 ***