Hi, could try starting firefox in safe mode please. See: Diagnose Firefox issues using Troubleshoot Mode

I loaded in safe mode and would say I couldn't get the problem to duplicate, but it only pops up from time to time. It will happen on a wide variety of websites.

Deleted (cross-posted)

Note: I had posted a link to http://kb.mozillazine.org/Firefox_hangs#Problematic_plugins because your plugins list shows the WebEx plugin. I then deleted my post after I saw that you can run Firefox OK in Diagnose Firefox issues using Troubleshoot Mode (plugins still remain in effect in Firefox Safe Mode).

If you no longer see the problem when your run in Firefox Diagnose Firefox issues using Troubleshoot Mode but the problem returns when you start Firefox normally, see Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems for possible causes and solutions.

So I got rid of all the extras and have the default theme set and it still froze. Now what?

Hi, When Firefox is freezing, is it actually crashing and closing down? If it is, open up Firefox and navigate to about:crashes

Once you are there, please copy and paste the first three crash ids to this question thread, and I'll try and interpret the crash report.

It freezes and I have to force shutdown the computer, when I go to crashes the last report shows January.

Hi, How old is your computer?

It's still under applcare, so not too old. It's an iMac running 10.6.8.

Okay. Sorry, but I'll have to leave this for somebody owns a mac now, I can't really suggest where to look for some information about processes etc.

Did you try to disable hardware acceleration?

• Firefox > Preferences > Advanced > General > Browsing: "Use hardware acceleration when available"

Already disabled

kthersh,

Does the problem with a hang in one program (Firefox) causing other running programs to hang, which then causes the entire Mac Operating System to hang, happen with any other program besides Firefox? In other words, if you browse using Safari or another browser, does the problem go away?

You said the problem goes away in Firefox Diagnose Firefox issues using Troubleshoot Mode .... is that still the case? I just wanted to make sure you aren't talking about Mac OS X Safe Mode .

If the problem only happens when you use Firefox or if you aren't sure if it goes away in Firefox Diagnose Firefox issues using Troubleshoot Mode because it only happens from time to time, there are a few other Troubleshoot and diagnose Firefox problems steps you can try ... for example, troubleshooting plugins, a clean reinstall of Firefox or creating a new Firefox profile (see the linked article for details).

You could also try a Mac forum such as discussions.apple.com to see if anyone has had a similar problem with Firefox 12 or if anyone has a Mac-specific solution to suggest.

I have the same issue. Here is a snapshot of my ecosystem: Macbook Air, OSX 10.7.4

I started using Trend Micro Smart Surfing for Mac in and around the time I upgraded to Firefox 12.

My typical open application set is: Outlook 2011, Mail and Firefox (with multiple pinned app tabs).

My crash behaviour is just like the others are describing above.

cpdesjardins, You said "crash behaviour". See Troubleshoot Firefox crashes (closing or quitting unexpectedly). Since your issue may be different you should probably start a new thread and describe the problem in detail. You can use this link as a starting point: https://support.mozilla.org/en-US/questions/new

I see no reason to start a new thread. Firefox crashes unexpectedly, just as described by the other poster above. No crash log is created because the whole system hangs for unknown behaviors, i.e. opening new tab, selecting link, refreshing page, changing tab. It is non-specific or non-apparent.

Macbook Air, OSX 10.7.4 Firefox 12 Trend Micro Smart Surfing for Mac

My typical open application set is: Outlook 2011, Mail and Firefox (with multiple pinned app tabs). Sometimes I have VMWare Fusion 4.1.2 open running a Windows 7 VM but this is not correlated to the crashes.

I have one add-in: One Password 3.8.19

My system knows it has crashed since following a hard reset, it reopens my previously open windows but no crash report is created or offered.

Safari does not crash the system.

cpdesjardins, I don't have anything else to suggest, other than what I wrote to kthersh in my post dated May 15, 2012

In frustration, I have started a new thread.