Try disabling graphics hardware acceleration in Firefox. Since this feature was added to Firefox it has gradually improved but there are still a few glitches. You will need to restart Firefox for this to take effect so save all work first (e.g., mail you are composing, online documents you're editing, etc.,) and then perform these steps: # Click the menu button [[Image:New Fx Menu]] and select ''Options'' (Windows) or ''Preferences'' (Mac, Linux). # Select the ''General'' panel. # Under '''Performance''', uncheck ''Use recommended performance settings''. Additional settings will be displayed. #;[[Image:Fx55Performance-disableHWA|width=500]] # Uncheck '''Use hardware acceleration when available'''. # Close Firefox completely and then restart Firefox to see if the problem persists. If the problem is resolved, you should check for updates for your graphics driver by following the steps mentioned in these Knowledge base articles: * [[Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems#w_turn-off-hardware-acceleration]] * [[Upgrade your graphics drivers to use hardware acceleration and WebGL]]