When I click the arrow for a drop down menu, it flashes on and back off. I cannot get the drop down menus to appear so I can use them.
All drop down menus are having this problem. The menu will appear and rapidly turn back off. Just a flicker. I cannot make a choice on any menu because it doesn't stay on.
Wšykne wótegrona (2)
Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of your add-ons is causing your problem (switch to the DEFAULT theme: Tools > Add-ons > Themes).
See Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems and Troubleshoot issues with plugins like Flash or Java to fix common Firefox problems
If it does work in Safe-mode then disable all your extensions and then try to find which is causing it by enabling one at a time until the problem reappears.
You can use "Disable all add-ons" on the Safe mode start window to disable all extensions.
You have to close and restart Firefox after each change via "File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit")
Here's the fix:
Eric714 posted this solution: Running Windows 7 64-bit and drop down menus in Firefox 4.0 disappear. Fix this by disable hardware acceleration in Firefix.
Tools -> Options -> Advanced -> General -> Browsing: Disable “Use hardware acceleration when available”
Credit goes to Daniel here: http://headadmin.net/?p=323&cpage=1#comment-9026
Note: Wish Mozilla could group all the questions related to this issue together so easier to see causes/solutions.