I have the same exact problem. Still looking for a solution.

Arun, have you read this post? If it didn't help, please go into Help > Troubleshooting Information... (alternatively, access about:support in your location bar) and click "Copy all to clipboard". Then paste here. Hopefully that will give me a bit more information to work with.

i had the same problem. i fix it by downgrading to 3.6.3. a sec ago when i thought id upgrade again and upgraded to 3.6.6 i got the same problem so i downgraded again.

  1.  Go to the Mozilla FTP server.
  2. Choose the version you want.
  3. Choose the win32/mac/linux-1686/ folder
  4. Choose your language. en-US is US English.
  5. Choose the file that does not end in .asc. The download will then start.
  6. Once the file is downloaded, install it. 

After downgrading, if you intend to stay with that version, you will need to turn off Software Update.

Version 3.6.3 is not recommended as it doesn't contain the latest security fixes. If you want a Firefox version without plugin isolation, please use version 3.5.10.

Same problem with Windows 7

I am now mostly using Iron for my browsing simply because Firefox is getting way unstable 

I have the disconnetion issue as well

Strant, please read this post.

The issue here is still that the plugin container in v3.6.6 crashes and takes the rest of Firefox down also, which is not what is supposed to happen. From the docs: "In Firefox 3.6.4 and above, some plugins are loaded separately from Firefox in plugin-container.exe, allowing the main Firefox process (firefox.exe) to stay open if a plugin crashes." It does not work as advertised. In addition, blaming this problem solely on buggy plugins doesn't make sense, since re-installing v3.6.3 over v3.6.6, as a test, without downgrading plugin versions, eliminates the crash problem. Plugin-container.exe needs to be fixed.

I have the same problem. Also, when firefox reloads, google toolbar will ask to translate webpages already in English into English and I will have to tell it to never translate English into English. Is Google Toolbar to blame?

i have the same problem using 3.6.6

I have had the same problem with Firefox version 3.6.6. When I go to a page with Flash video it freezes. I then have to close down Firefox via Task Manager.

I then get the message "Plugin Container for Firefox has stopped working".

Like other people I have resolevd the problem by downgrading to an earlier version of Firefox. And with version 3.5.10, which is recommended on this page for security reasons, I do not get the problem.

But how will I know when to upgrade to a later version (ie later than version 3.6.6) and still not have the problem?

David, your issue will only be fixed in versions after 3.6.6 if the issue is caused by a problem with Firefox. To know if it is a problem with Firefox or with an add-on, please read this post. Post the results if you wish for further help.

If it's a problem with an add-on, it will never be fixed by just updating Firefox alone. You need to update the problematic add-ons, and if their latest versions are still causing problems, disable them altogether.

Same problem w/3.6.6

I got that problem when i go in fullscreen while watching videos, at internet explorer it's the same even some of my games won't start anymore.Like if i want to play spore it always says: "SPORE has stopped working"

it sucks. I always thought Firefox was exceptional...now it seems to keep developing more and new glitches, routinely. Where is the solution for this plug-in container/crash/sound situation???

Here hopefully.

There are those of us with moderate computer skills who are unwilling to spend the time to disable all plug-ins; it is simply not worth dealing w/a program that crashes every 5-10 min. & requires task manager to close. I suggest chrome -- takes some getting use to but DOES NOT CRASH.

If you have a problem with Google Chrome, you need to contact Google, since they are the ones that develop it. Be mindful that the big amounts of RAM it uses up when browsing multiple tabs is not a bug, but rather a "feature" of Chrome. Also, be mindful that the impossibility of having many tabs in the same window is not a bug, but rather a "feature" of Chrome. Bear in mind, in addition, that the relatively poverty of add-ons for Google Chrome is not as much due to its age as it is to the impossibility of developing add-ons for it that are as rich as those for Firefox. Don't forget either that the fact that Chrome will send, by default, potentially private information to Google is not a bug, but rather a "feature" of Chrome. You may also end up finding the very same problems you found in Firefox, if those were due to careless usage of add-ons or an infected system. For any usability problems, you will need to contact Google directly, too.

Also, if you are using another browser out of spite or because you can't fix your problem with Firefox, I will remind you that Mozilla is a non-profit, public service organization, and, as such, doesn't have the same financial interests Google (or any other company developing a major web browser) does. Mozilla's objective is that you, the user, use the browser you want, be if Firefox or any other browser. If you want to use Firefox but can't, due to a problem, I'm glad to work with you the best I know and can to fix it. If you actually want to use another browser, then I'm happy that you finally found your "home", and my job is successfully done.

yh will you lot sort this coz it taking the PISS >.< im leaving the program if you dont bring out an update soon i cant do fuck all on the net now THANKS A LOT!

Same problem using facebook and facebook apps. crashed 5 times in 15 minutes...

Who said Google Chrome crashes -- CHROME DOES NOT CRASH -- a willful misinterpretation of the post. FF CRASHES! I for one have no intention of fooling around disabling recommended plug-ins. I have chosen in the past to be a beta tester but not this time.