BSOD on Windows XP 64-bit

I am getting more or less randomly BSODs on Windows XP 64-bit.
I am running the system normally as a normal user and I've run memtest86 for many hours without problems.
Yet I get different sorts of BSOD (just to show a few: http://eonwe.pp.fi/images/album/bsod/) at rate of ~1 / week.
Earlier I did not get any minidumps because I did not have paging file enabled.
I've now enabled the paging file and gotten my first BSOD afterwards. The dump is available from http://eonwe.pp.fi/pub/Mini062408-01.dmp and I've run it through windgb and got following info:

This does not tell me much especially as the run process was opera.exe.
I am posting here in hope of getting some ideas what to look for or to try out. So if you have such ideas, please let me hear them.

 

you say random? what were you doing in opera when it happened? Most common (IMO) bsd's are caused from video drivers...check for updates...and audio too. or check for something like updates for flash, Sun Java, etc.

 

Yeah, quite random. As you can see from the screenshots, actual error messages vary. I've got WHQL NVIDIA drivers and when they crash (not happened to me, but to others) the cuplrit is usually shown as nvsomething.sys or something like that.

I wouldn't think that Java and other stuff that run in user-mode can actually crash windows.

 

I got one more crash :cry. Seems like that faulting process has nothing to do with the problem as now it was MSN Messenger. The dump can be found at http://eonwe.pp.fi/pub/Mini070508-01.dmp if anyone has any ideas.
I am running Windows XP professional 64-bit on Asus P5B, 4 x 1 GB of memory and C2D E6600 + GF 7300GT. I've got the latest drivers from Asus and Nividia.

 

One more thing:
In some cases when I've run prime95 torture test (blend) with two prime95 instances, both running on their own cores, I've gotten that dreaded "Possible hardware failure, consult the readme file." error message with incorrect value.
All this could point to cpu, memory or motherboard (corrupting memory) failure. I can normally run prime95 torture indefinetly, it fails only occasionally so I would not think that cpu would be the cause as I would be seeing more crashing in other programs too then.
I've run memtest86 successfully for 8 or so hours so my guess based on these would be faulty driver or bad motherboard. Any comments?

 

Everything working ok now.

Well, I bought a new motherboard and everything seems to be working fine now. A bit hard to say what actually was the problem with motherboard, only that it probably was the cause.