It also gives me a unresponsive script message and makes Firefox hang when I tested it. The related bugs are mentioned in the report, but not all of them are visible. All the stack tells is that it something in the javascript of the page. I was using beta, there might be an improvement in performance there however in order to better investigation, #Does this happen in Safe Mode? [[Troubleshoot Firefox issues using Safe Mode]] # Does this happen with hardware acceleration - [https://support.mozilla.org/en-US/kb/upgrade-graphics-drivers-use-hardware-acceleration please try updating your graphics driver.] or disabling hardware acceleration.