Please check if all your plugins are up-to-date. To do this, go to the [http://mozilla.com/plugincheck Mozilla Plugin Check site]. Once you're there, the site will check if all your plugins have the latest versions. If you see plugins in the list that have a yellow ''Update'' button or a red ''Update now'' button, please update these immediately. To do so, please click each red or yellow button. Then you should see a site that allows you to download the latest version. Double-click the downloaded file to start the installation and follow the steps mentioned in the installation procedure. ---- 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.