You can check for problems caused by a recent Flash 11.3 update and possibly downgrade to Flash 11.2 or 10.3.

• https://support.mozilla.org/kb/flash-113-doesnt-load-video-firefox
• https://support.mozilla.org/kb/flash-113-crashes

• http://blogs.adobe.com/asset/2012/06/inside-flash-player-protected-mode-for-firefox.html

Try to "disable the hardware acceleration" in the Flash Player.

• http://helpx.adobe.com/flash-player/kb/video-playback-issues.html

See also:

• https://support.mozilla.org/kb/keep-flash-up-to-date-and-troubleshoot-problems

Flash "Display settings" window:

• http://www.macromedia.com/support/documentation/en/flashplayer/help/help01.html

Try to disable hardware acceleration in Firefox.

• Tools > Options > Advanced > General > Browsing: "Use hardware acceleration when available"
• https://hacks.mozilla.org/2010/09/hardware-acceleration/

• https://support.mozilla.org/kb/how-do-i-upgrade-my-graphics-drivers

Thank you cor-el for your reply. First off, I'm using version 3.5 because the newer version 13 actually causes more problems with my video-audio viewing (out of sync and freezes) more then version 3.5. It seems 3.5 has less of the problem, weird? I tried disabling hardware accelerator in both flash player, and that had no difference on the issue. When I tried to disable hardware accelerator in firefox, following the instructions, I wasn't able to access it in the browsing section of the advanced tab. I wasn't given that option, in the three options offered? So, I can't comment on that possibility cor-el. I spent quite a bit of time, making sure I had new updates, and new plug-in updates on my system this morning. All of which made no difference in the problem? My system is an old computer. Am I beating an old horse here, because of that. My internet connection is not slow (charter) if that would have anything to do with it? I'm not a pro at solving computer problems. But, given good instructions I believe I can try various solutions to see if they can remedy the problem. What suggestions do you have cor-el? Again, thank you.

Pretty much all of the suggestions on fixing out of sync video/audio don't work. There is something wrong in the software that can't be fixed locally. I have a notebook running Windows 7, IE and Intel i5 and there is no problem with the audio/video. Windows XP started having these problems this spring. Last year there was not problem. Most likely all of this is due to continual upgrading of software. What a mess.

Hi navydisposalee,

You're probably right. Also, my system is an old system and I'm pretty sure that is adding to my problem. When I upgrade to a new system, I suspect that may help. But, it may not if windows XP is actually at fault. Thanks for your reply.

I'm not sure if it's a XP problem. Adobe Flash Player has been suspected as the problem but I've tried using various versions of Flash Player and that does not help. Oddly enough, some video/audio web sites work just fine while others are out of sync. That indicates to me a problem with "standards of practice" being used by web designers or servers could also cause sync issues.