Are you running Firefox with a maximized window?

Try to disable transparency in Windows, see:

• [/questions/804050]

Right click in a free space on your desktop.
Left click on Personalization.
There are four options at the bottom of the screen, choose "Window Color and Appearance".
Select a border color
Uncheck: "Enable transparency"

You can try this theme:

• Firefox 3 Aero theme for Firefox 4+: https://addons.mozilla.org/firefox/addon/firefox-3-aero-theme-for-fi/

I may have described the problem wrong. Before FireFox updated today 4/4/2012, I had no problem with Tabs. Now, when I open a Tab and hover the mouse pointer over it, I get a minimized screen view of what's on that Tab. When I try to close the Tab, it keeps showing this minimal view (cycles on and off), interfering with the closure of the Tab. Some may like this, but my eyes are getting tired from watching this activity, I have no use for it and believe that it is a little tooooooo helpful and wish to turn this feature off?

If I understand correctly, you're referring to either of two things:

• Windows 7 has a feature where if you hover over an item in the taskbar, it shows you a thumbnail of the window. With Firefox, it shows a thumbnail of every tab. But Firefox has supported that feature since Windows 7 was released. It's not new. You can turn it off:

1. In the Location bar, type about:config and press Enter. The about:config "This might void your warranty!" warning page may appear.
2. Click I'll be careful, I promise!, to continue to the about:config page.
3. Search for the preference: browser.taskbar.previews.enable
4. Double-click on it, to change the value to false.

• Another possibility is that what you're describing was added by an extension. If you close Firefox, then start Firefox in Safe Mode, does the problem still occur? To start in Safe Mode, go to Firefox > Help > Restart with Add-ons Disabled.

If the problem does not occur in Safe Mode, then you can disable your extensions one-by-one until you find out which one is causing the problem. See Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems.

Thank You, everyone. It was an extension I had added. I don't normally add a lot of "baggage'" to my browser, but this was a new extension I wanted to try, FVD Suite addon. It has an options panel to disable. I had installed this about the same time FF updated, so I was looking in the wrong direction.