• "Clear the Cache": Tools > Options > Advanced > Network > Offline Storage (Cache): "Clear Now"
• "Remove the Cookies" from sites that cause problems: Tools > Options > Privacy > Cookies: "Show Cookies"

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).

• Don't make any changes on the Safe mode start window.

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.

• Use "Disable all add-ons" on the Safe mode start window to disable all extensions.
• Close and restart Firefox after each change via "File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit")

Good grief - so your answer is that I hire a computer tech to work on my computer - is THAT it?

I'm a computer novice who religiously cleans her cache. I've checked everything I know to check - but how in heaven's name do you independently cause Firefox to go into something called "Safe Mode?"

What the heck is a "Linux?' An "extentions?" I haven't the money for a computer tech! Why did YOU break MY computer???Everything on my computer was there BEFORE THE FIREFOX UPDATE LAST NIGHT... and now only ONE site has trouble AFTER the update last night. Nothing else changed but YOU.

The next day - The pop-up player on the MySpace site in question played with my FireFox browser - after no work handled by me.

Today - it refuses to play videos ONLY on CMT.com... nowhere else.

There's a bug in Mozilla Firefox - and I certainly hope y'all find it!