Exactly like the title says. It does not happen when scrolling down, or when using the arrow keys on my keyboard (it is not my mouse causing it, I've tried others...)
Here are some things I've tried, that didn't yet solve anything.
- Versions: 10.1.82.76, 10.3.183.67, 11.2.202.233, 11.6 (beta) and the latest; 11.7 (beta) (I followed the instructions on this article before each re-installation and even ran CCleaner before as well.)
- Downgrade Firefox to 18.0
- Set ProtectedMode to 0
- Disable/Enable smooth scrolling
- Disable/Enable hardware acceleration
- Create a new Firefox profile
- Run Firefox in safe mode
I've tried out the same browser/Flash version combination that I was using before I recently re-installed my OS (Firefox 18 with Flash 11.6 beta) which worked fine, but somehow it's not the same...
I have had this problem in the past. It went away after a long time, but I have absolutely no idea what solved it. Also, in other non-IE browsers (Chrome) it's completely fine.
My graphics drivers are the latest available, including the drivers for all of my other components.
So what else can I try now... ? Is there a specific Windows update I should have installed?
Firefox: 19.0.2
OS: Windows XP Professional SP3 (x86)
Here is a video that shows the phenomenon: http://dl.dropbox.com/u/48454461/vid/flashbug.avi
(The first time I scroll down and back up, I use the mouse wheel -- the second time, I use the keyboard arrows)
YouTube isn't the only place this happens at. Also, I do not have this problem with the built-in Flash player in Firefox (19), but Firefox tells me "additional plugins are required" when I don't have the official Flash player installed, so...