Hello,

Try Firefox Safe Mode to see if the problem goes away. Firefox Safe Mode is a troubleshooting mode that turns off some settings and disables most add-ons (extensions and themes).

(If you're using an added theme, switch to the Default theme.)

If Firefox is open, you can restart in Firefox Safe Mode from the Help menu by clicking on the Restart with Add-ons Disabled... menu item:


If Firefox is not running, you can start Firefox in Safe Mode as follows:

• On Windows: Hold the Shift key when you open the Firefox desktop or Start menu shortcut.
• On Mac: Hold the option key while starting Firefox.
• On Linux: Quit Firefox, go to your Terminal and run firefox -safe-mode
  (you may need to specify the Firefox installation path e.g. /usr/lib/firefox)

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 Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article to find the cause.

To exit 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 others with the same problem.

Thank you.

Thanks for replying but this doesn't solve the issue. I have very few add-ons: only three actually: Adblock Edge + Helper for hiding ad elements, and an add-on for my electronic signature. I am not using any themes. There is nothing external that could be blamed for the text-rendering problem.

I have just updated the video graphics software - my previous attemt seems to have been unsuccessful - this time I removed the driver completely, rebooted, installed a fresh copy, rebooted, made sure I was running the latest version.

The text smudging problem still occurs but not on large portions of text - only on a couple of lines. I guess I will have to live with it, or change the browser.

You may have zoomed the page(s) by accident.
Reset the page zoom on pages that cause problems.

• View > Zoom > Reset (Ctrl+0 (zero); Command+0 on Mac)

• http://kb.mozillazine.org/Zoom_text_of_web_pages

Thanks, but no, that's way too obvious not to spot in so many days, even after one Firefox upgrade.

Does it help if you disable smooth scrolling?

• Tools > Options > Advanced > General: Browsing: "Use smooth scrolling"

Try to set the gfx.content.azure.enabled pref to false or if this didn't help disable Direct2D by setting the gfx.direct2d.disabled pref to true on the about:config page and leave hardware acceleration otherwise enabled.

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

You can also try to uninstall Windows update KB2670838 if you have this update.

• http://support.microsoft.com/kb/2670838

Thanks for the suggestions! 1. I tried disabling smooth scrolling - the problem persists. 2. I could not find this settings: gfx.content.azure.enabled. There is only "gfx.content.azure.backends". 3. I also tried changing "gfx.direct2d.disabled" to "true". Still no change. 4. I do have this Windows update. I have not tried disabling it. Might try tomorrow.

This is really annoying. How can Chrome, Opera and even Internet Explorer perform well, but Firefox can't...

Sorry, you can no longer disable Azure by setting gfx.content.azure.enabled to false.

You can try the suggestion in comment 414 in bug 812695:

• https://bugzilla.mozilla.org/show_bug.cgi?id=812695#c414

I created a new boolean called "layout.paint_rects_separately" and set it to "true". I haven't done much testing yet -- just opened FB a couple of times -- but I don't notice any smudging. Let's say problem solved! I will write again here if it re-occurs.

Thank you!