Hi, if you have a theme, try disabling it. ------------------------ Also try disabling graphics hardware acceleration. Since this feature was added to Firefox, it has gradually improved, but there still are 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.). Then perform these steps: #Click the menu button [[Image:New Fx Menu]] and select ''Options'' on Windows or ''Preferences'' on Mac or Linux. #Select the ''Advanced'' panel and then the ''General'' tab. #Uncheck '''Use hardware acceleration when available'''. #Restart Firefox and see if the problems persist. 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]] ''If your question is resolved by this or another answer, please take a minute to let us know. Thank you!''

It was hardware acceleration. thanks a lot.