Hello marchsmaggie, try disabling graphics hardware acceleration.

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:

1. Open Firefox Options window as follows:
2. In Firefox 29.0 and above, click the menu button and select Options.
3. In the Firefox Options window, click the Advanced tab, then select General.
4. In the settings list, you should find the Use hardware acceleration when available checkbox. Uncheck this checkbox.
5. 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

Thank you.

See if there is an update for the graphics display driver.

• https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration

Try to create a new Boolean pref on the about:config page via the right-click context menu with the name layout.paint_rects_separately and set the value to true and leave hardware acceleration and Direct2D enabled.

• about:config page: layout.paint_rects_separately = true

Try to disable Direct2D and leave hardware acceleration enabled

• about:config page: gfx.direct2d.disabled = true

That way you still have the benefit from hardware acceleration, but may not suffer from rendering issues.

You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.

• http://kb.mozillazine.org/about:config