Random BSODS on new build - passing tests, but still crashing

[mediv42]

Hi everyone, Ive been getting some bsods, maybe one a day. They happen when i'm not overclocked and when im overclocked, I've played crysis for hours with no problem at 1920X1200, but other times when im just surfing and listening to music, bam: bsod. In fact, two others came with little/no stress on the system, and one came on shutdown.

I pass memtest86+ and prime95 for 9+ hours
Realtemp reports 36C idle, 49C max load

Heres my build:
CM 690 case
CM realpower Pro 550W
E8400@3.6 with xigmatek HDT-S1283
4gb gskill (2x2) had errors on memtest at 1.8v, fine at 1.9v
gigabyte EP43-DS3L
sapphire HD 4870 with fanspeed set to 45%
pioneer blu-ray
segate barracuda 750 gig

typically seems to be BCCode: 1a, a memory management error, but memtest passes?

If I open the .dmp files windbg tells me 1x ntkrnlmp.exe is the cause and 3x memory corruption (4 bsods so far)

So I would suspect the power supply, except the crashes happen when I'm basically doing nothing, not when I'm stressing it. It's about a week old build... so really anyone have some ideas what else I can test to find what might be wrong, or even which part i should RMA?

 

[MysteriousWind]

what OS are you running?

Was everything seated solidly when you did your build (I doubt this would be it but it's worth double checking)?

ntkrnlmp.exe is related to windows if I'm not mistaken. Where there any errors when you installed Windows? If you can, run scandisk on your HDD.

In device manager are there any problems, and did all of your driver installations go smooth?

 

[mediv42]

running vista home premium x64

I re-seated the cpu cooler to check if i had the as5 on correctly, looked great, (of course now i cleaned, re-applied, and who knows if i got it right again)

I'll check the cards/plugs/ram

no problems in device manager

 

[MysteriousWind]

Could you post your minidumps? Also, it may be worth updating your drivers.

If you think it's your PSU, there are ways to check it, but as you said it's weird that it didn't happen under load.

Are there any definitive actions that will make it BSOD?