One of the crash reports indicates a possible issue with hardware acceleration and Intel drivers. I'm not sure if safe mode disables hardware acceleration, but as a test, whilst in safe mode, disable hardware acceleration, then see if Firefox runs OK in normal mode. The setting to disable hardware acceleration is in the Options dialog, on the Advanced panel, General tab.

The info about hardware acceleration came from one of your crash reports which pointed to this bug - Bug 590373 – Crash [@ _VEC_memzero] on startup with D2D enabled and MS performance hotfix installed

Hmmm thanks, that actually seems to help so far! Disabled hardware acceleration on all the profiles, and haven't had any of them crash in Beta or Minefield yet... :)

Should I report this bug, or would my crashlogs be enough? And how would I know if the bug is fixed; just retry after every update, or is there somewhere I can follow the progress?

The crashlogs will be enough, and there is already a bug report concerning the crash signature that you have. Mozilla believe it is a driver issue, see the bug report that I posted a link to on my first reply for details.

I installed every day the new update of Firefox x64 for Windows. The last working version was firefox-4.0b7pre.en-US.win64-x86_64.installer.exe of 02.Oct 2010. Every version since then crashes immediately after startup on two different machines.

@aaa..., did you disable the hardware acceleration in Firefox?

I'm having the same problem: EVERY version of Minefield from 2nd October onwards crashes whenever I try to view a page (even the Addons page), and the 1st October nightly build is the last stable version for me (I'm using it now). The worst thing is, Windows shuts it down rather than it coming up with Firefox crash assistant, so I have nothing to present other than the contents of Event Viewer:

Faulting application name: firefox.exe, version: 2.0.0.3932, time stamp: 0x4cada64f Faulting module name: mozjs.dll, version: 0.0.0.0, time stamp: 0x4cad9ae3 Exception code: 0xc0000005 Fault offset: 0x00000000001ab60e Faulting process id: 0x1218 Faulting application start time: 0x01cb6652930b2207 Faulting application path: C:\Program Files\Minefield\firefox.exe Faulting module path: C:\Program Files\Minefield\mozjs.dll Report Id: d6ab44a7-d245-11df-b9e4-e2f84d3d7187

I'm using 64-bit Win7 Pro. And yes, I've tried turning off hardware acceleration... did something major change on 2nd October?

I get the same experiences as Dave -ros. Safe mode is working. Hope the team can find the work arround. thanks to all for your hard and excellent work.

i have found interesting information here.

it seems that disabling both

 javascript.options.methodjit.content

and

 javascript.options.methodjit.chrome

circumvents the crash. (i suspected the crash to be related to javascript, because typing in the google instant box crashed the browser)

I can report that the solution relayed by Mr. Airborne Ovine works (though only one of the options was true to begin with for me -- I think .content was already false), and I'm now using 4.0b8pre without issues. Huzzah!

Now, if only my ISP weren't having problems tonight... :-(

Felet uppstod i programmet med namn: firefox.exe, version 2.0.0.3933, tidsstämpel 0x4caee8d2 , felet uppstod i modulen med namn: mozjs.dll, version 0.0.0.0, tidsstämpel 0x4caedd52 Undantagskod: 0xc0000005 Felförskjutning: 0x00000000001ab60e Process-ID: 0x194c Programmets starttid: 0x01cb67325561d3ce Sökväg till program: C:\Program Files (x86)\Minefield\firefox.exe Sökväg till modul: C:\Program Files (x86)\Minefield\mozjs.dll Rapport-ID: 94e7c896-d325-11df-a1ae-001fbc00af4c

Same on firefox-4.0b8pre.en-US.win64-x86_64.

It also crashes if I disable hardware acceleration. One of my machines is nvidia, one ati.

If I start safe-mode it doesn't crash but if I start safe-mode, check all checkboxes and press restart it crashes again. It also crashes if I delete places.sqlite.

Have you tried disabling the two Java options under about:config, as above? Worked for me...

Changing javascript.options.methodjit.content to false solved the problem!

the same questions mozjs.dl but to false the javascript and solve this, amazing! Thanks a lot.

hmm...

same stuff, same problem.

harware accel: on java: off

Problem signature:

 Problem Event Name:	BEX64
 Application Name:	firefox.exe
 Application Version:	2.0.0.3938
 Application Timestamp:	4cb573b1
 Fault Module Name:	StackHash_d918
 Fault Module Version:	0.0.0.0
 Fault Module Timestamp:	00000000
 Exception Offset:	0000000006ee73f0
 Exception Code:	c0000005
 Exception Data:	0000000000000008
 OS Version:	6.1.7600.2.0.0.256.1
 Locale ID:	16393
 Additional Information 1:	d918
 Additional Information 2:	d918257796f6131203ab236b9b32dce9
 Additional Information 3:	3a2b
 Additional Information 4:	3a2bb3a14f9c4660213f12279fe67f76

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Open this link: http://fallout.wikia.com/wiki/Restoring_Hope

When scrolling the page, the newest Minefield 4.0b8pre crashes! :(

I also noticed that this browser started to crash very often... Btw, there is also another problem, that was before: after some time of working, it spoils graphics on a screen - tabs, icons, etc are not fully drawn, duplicating, etc...

No problems here with Minefield on Linux.
There are some Flash objects on that page, so you can try to disable the Flash plugin (Tools > Add-ons > Plugins).
You can also try to disable the hardware acceleration:
Tools > Options > Advanced : General: Browsing: "Use hardware acceleration when available"

See also http://kb.mozillazine.org/Plugin-container_and_out-of-process_plugins