Hello, Try disabling graphics hardware acceleration. Since this feature was added to Firefox, it has gradually improved, but there still are a few glitches. You might need to restart Firefox in order 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 orange Firefox button at the top left, then select the "Options" button, or, if there is no Firefox button at the top, go to Tools > Options. *In the Firefox options window click the ''Advanced'' tab, then select "General". *In the settings list, you should find the ''Use hardware acceleration when available'' checkbox. Uncheck this checkbox. *Now, restart Firefox and see if the problems persist. Additionally, please check for updates for your graphics driver by following the steps mentioned in the following Knowledge base articles: [[Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems]] [[Upgrade your graphics drivers to use hardware acceleration and WebGL]] Did this fix your problems? Please report back to us! Thank you. _________________________________________________________________________________ '''Try Firefox Safe Mode''' to see if the problem goes away. Safe Mode is a troubleshooting mode, which disables most add-ons. ''(If you're not using it, switch to the Default theme.)'' * You can open Firefox 4.0+ in Safe Mode by holding the '''Shift''' key when you open the Firefox desktop or Start menu shortcut. * Or open the Help menu and click on the '''Restart with Add-ons Disabled...''' menu item while Firefox is running. ''Once you get the pop-up, just select "'Start in Safe Mode"'' '''''If the issue is not present in Firefox Safe Mode''''', your problem is probably caused by an extension, and you need to figure out which one. Please follow the [[Troubleshooting extensions and themes]] article for that. ''To exit the Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.'' ''When you figure out what's causing your issues, please let us know. It might help other users who have the same problem.''