in safe mode the flickering stops. must be an add on.

safemode is a bit drastic, for me disabling hardware acceleration did the trick. Click the orange menu button goto options -> options then click the advanced button in the upper right then there is an option in somewhere in the middle about hardware disable it by unchecking the box and press OK. Remember to try and re-enable it after every update because hardware acceleration dramaticly improves the performance of the browser

Instead of waiting for an update to firefox you could also try to update the driver for your grapicscard and see if this enables you to do the hardware acceleration without problems.

~edit: i'm colourblind the firefox menubutton is of course orange and not yellow, added protip for graphicscard drivers.

"... disabling hardware acceleration ..."

Thanks for the fix! My Firefox 4 menu was flickering, as were drop-downs. It was hard to use a transparent menu! Got pretty annoying. Now everything is working fine.

Thanks a lot for the quick responses. I have tried the disable hardware acceleration, and that cleared up the problem! Thank you :)

For me, full screen mode stops the flickering, although it won't show certain toolbars in that mode. To get in, hit the Firefox tab in the upper left corner and you will see the Full Screen Mode button in the list of choices. To get out, move your mouse to the top of the screen, find a space up there that doesn't have a tab or button on it and right click. You should be able to hit a choice called Exit Full Screen Mode. If you don't see it, fiddle around by right clicking in spaces some more until you do. First thing I'm going to do is see if I can't put a button on the toolbars to allow me to easily switch modes.

This version of Firefox is remarkably unstable for me compared to previous versions. I had no problem at all with the older versions.

Well it seems im not the only one with the flickering problem. I never had the problem with the 3.6 version. I installed version 4 and i began to get constant flickering. At first i thought it was my video drivers, so i updated it. But the problem wasnt solved. Still flickering screen. Even when i closed Firefox. So i decided to uninstall 4 and install 3.6 back again and voila, the problem was gone. No more flickering screen. So they really need to look at this problem.

I have a Dell XPS M1530, Windows 7 - 64bit, Nvidia 8600M GT, 4GB Mem

I had the problem with the flickering menus too. Turning off hardware acceleration "fixed" the problem.

Strangely enough, the flickering only is a problem on my secondary monitor. On my primary monitor, firefox 4 works even with hardware acceleration turned on.

Also having this problem on my MacBook pro.

https://support.mozilla.com/nl/questions/786535

It's an issue that is happening on almost all MacBooks!!

wow, finaly! the hardware acceleration was my problem too!

HEADS UP !!!

The problem, especially on MacBooks (a few years old) is usually do to failures by the

NVIDIA GeForce 8600M GT

graphics card (hardware).

Apple, HP, and others have settled a class-action lawsuit in this regard, and will replace the mother-board or the entire laptop (often easier). HP and others with this problem should search this and related paths to see if it applies.

In any case, make sure that all backups are current and frequently updated as this may be a warning sign of an imminent failure -- and since it's on the mother-board, the whole machine may suddenly cease to boot, safe-mode or not.

... addenda:

this happened to me, and Apple "fixed" my laptop (still under Applecare), though the settlement should protect anyone Applecare or not.

Firefox just exercised something thru the graphics-card that triggered the flickering behavior.

Remember that old saying, "correlation is not causation".  ;)

I've had the same problem as you. If you have any themes such as Stardock MyColors installed on your computer, try restoring it to you default Windows Aero Theme (For Win7 and Vista). I had MyColors installed and I got the flickering screen when you scroll etc.

@Akopian

No need to put a button on your toolbar to toggle fullscreen, your keyboard already has one: F11.

I had this same issue. If you don't want to turn off hardware acceleration or work in safe mode, you can also go to your options menu and check the menu bar. That will also get rid of the flickering. With both solutions however, I still have an issue. With any menu (whether it's the right click menu or options menu or whatever) as my cursor scrolls over the choices they remain highlighted. Nothing that will keep me from using Firefox 4, but it is distracting and does detract from the experience.

Hello,

I may have the same problem. I think that it was not working well also after the last update of Firefox 3.6. Because I had problems with it I took Firefox 4. One day everything was working very well, but next day Firefox became very slow. In Windows Vista Task Manager it was not responding during some minutes. I was working like this about one week using also IE while Firefox was jammed. Today I was thinking what to do with this. First I simply reinstalled Firefox 4 without deleting the old one. Now it seems working very well again. I could not listen BBC or VOA during one week. Now BBC is working well. I hope Firefox is working still tomorrow fine. I will report if it is again jamming. I am just wondering what it could be.

I have disabled add-ons one by one to see if any was responsible for the flickering. I found that one add-on: ColorfulTabs 4.8.1.6.1 was causing the flickering issue, especially when I switched to IE Tab. Any of you have this add-on installed?

Solve blank / black screen problem while playing youtube videos in full screen mode by OriginalTips.com,

http://www.originaltips.com/youtube-black-screen-problem-on-fullscreen-solution-24