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Why am I getting vertical lines below each letter I type?

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  • 11 have this problem
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  • Last reply by cor-el

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I keep getting vertical lines below each letter that I type when filling in things with Firefox 4. There is one line created for each letter.

I keep getting vertical lines below each letter that I type when filling in things with Firefox 4. There is one line created for each letter.

All Replies (1)

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Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).

In Firefox 4 Safe mode disables extensions and disables hardware acceleration.

  • Tools > Options > Advanced > General > Browsing: "Use hardware acceleration when available"

If disabling hardware acceleration works then check if there is an update available for your graphics display driver.


In Firefox 4 you can use one of these to start in Safe mode:

  • Help > Restart with Add-ons Disabled
  • Hold down the Shift key while double clicking the Firefox desktop shortcut (Windows)