I experience more or less the same except that for me addititionally my whole pc (windows xp sp3) freezes.

It started with a crashing embedded youtube flash player, which was isolated by new FF method but even before I could click that link 'Report crash' within the flash player area ...my pc freezed. Had to reboot pc the hard way. I tried doing the same (watch embedded youtube movies) and the problem replicated each time. IMHO FF 3.6.6. is among the worst releases ever. The never-ending series of updates certainly does not improves my user experience.

Same problem here. I upgraded to 3.6.6 and now it crashes several times a day. It doesn't matter what I'm doing, it just crashes. I'm now looking at other browsers after using FF for 90% of my browsing since the early days of FF. :( Hope it gets fixed!

I'm having to switch to chrome to get anything done because it keeps on crashing on me. CB

Stopped crashing by disabing AVG Safe Search.

Updating AVG did not fix Safe Search.

This certificate message in FF 3.66 is driving me CRAZY!!!

Can't make it work with Flash 10.x: almost every flash site freezes FF 3.6.6 for a while and then shows an error message. Now I'm using Flash 9 but have to switch to Chrome to see Google Street View...

I gave up - switched to Chrome - so far, everything works now (now I have to go read those boards, just so I know what to expect ;->) Mac OS 10.4, previous FF 3.6.6. No issues using 10.6 on my company desktop with Windows. Whoever is in charge of FF these days appears to be second only to Apple in ignoring the blogs, as far as I can tell. Sorry to go but...

Typo - FF 3.6.6 on my other machine/Windows is working fine (sorry)

I'm very, very and truly sad and sorry to see that Firefox wants to throw in the towel and commit suicide. I actually un-installed Firefox for the first time in many years. Here's hoping for a quick fix to minimize loss.

Hey Mozilla Support - What's UP! Fix it or loose your favored standing with a lot of user!

I'm not sure what I hate more now, Windows or Firefox

Having the same problem. Every time firefox is crashing...maybe because flash plugin....

after upgrade to 3.6.6 suddenly Firefox hangs, particularly when playing a video. Am using Flash 10.1 r53, which according to the plugin update checker is the latest version. IE is working fine. computer runs on XP

Hello everyone.

It's possible that you are having a problem with some Firefox add-on that is hindering your Firefox's normal behavior. Have you tried disabling all add-ons (just to check), to see if Firefox goes back to normal?

Whenever you have a problem with Firefox, whatever it is, you should make sure it's not caused by one (or more than one) of your installed add-ons, be it an extension, a theme or a plugin. To do that easily and cleanly, run Firefox in safe mode (don't forget to select Disable all add-ons when you start safe mode). If the problem disappears, you know it's from an add-on. Disable them all in normal mode, and enable them one at a time until you find the source of the problem. See this article for information about troubleshooting extensions and themes and this one for plugins.

If you need support for one of your add-ons, you'll have to contact its author.

If the problem is not disappears when all add-ons are disabled, please tell me, so we can work from there.

Thanks for this, Morbus

This advice sounded helpful but, in safe mode and all add-ons disabled, the crash still occurs and the problem remains the same: Firefox crashes within a minute of opening.

The problem, evidently, is Firefox 3.6.6

Im on a mac 10.4 or I would have deserted to Chrome long ago

What now?

Can you please try it in a new (temporary) Firefox profile and see if the issue is still present? See this article to know how to create a new Firefox profile. Please report back the results.

Thanks Morbus

But I fell at the second post here. I cam exit Firefox but have no idea how to navigate (from where) to /Applications/Utlitiities. Is that a PC move?

If I can do this second step, the rest seems easy enough

Jim, you can configure what info is displayed in that article, depending on the system, where it says Show content customized for:

Just click your system and it should display what you need.

same problem. FF 3.66 randomly crash/closed automatically. Please Fix this ASAP. :(

I experienced this since FF 3.6

O/S: XP SP3 Proc: Intel Celeron M @1.7GHz RAM: 2GB

Please read this.

I'm annon above you Morbus. I even did fresh install FF 3.66 on new PCs (win 7) it's unstable and keep crashing randomly. I am sysadmin, I recommend users to switch back to IE if crash became very annoying.

The crash just random. on random website and situation.

well, IF it's not caused by addon, then FF 3.6x is Buggy Fox.