Hello,

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 Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems 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.

Thank you.

It is called a tooltip. I see much the same thing with SeaMonkey (but not with Firefox). My problem does not go away in safe mode.

I'm not seeing it on Windows 7. Could it be specific to a particular distribution of Linux?

It's not an issue with extensions or visual themes. It's Firefox.

I have had the same thing for a few day, probably since I updated to FF version 24.0. I'm using 64-bit Mint 15 "Olivia" (similar to Ubuntu 13.04 "Raring"). All previous versions of Firefox behaved normally (i.e. with a normal [small] tooltip).

It will probably disappear as mysteriously as it first appeared, soon.

I have the same problem (Firefox 25.0, Debian Wheezy), and I have found a work-around. I installed the extension "URL in tab tooltip" (see link below) and then deactivated it.

http://addons.mozilla.org/fr/firefox/addon/tab-tooltip/

Now my tab tooltips are displayed correctly. I had to remove and install again the extension after an upgrade of firefox.

I hope that helps to find the source of the problem.

Less than four weeks later, and with FF version 25 installed, it's fixed itself. Now it once again displays the tab name in the tool tip and is back to its proper size.

This is the setting in about:config that controls it:

• browser.tabs.tooltippreview.enable - set to false to make it normal sized