been running my 8400 for almost 2weeks with no problems

last 2 days I'm getting BSOD "IRQL not less or equal to" on a cold boot only, and have made NO changes to my setup. Once the pc heats up this goes away and it never happens the rest of the day. If however I turn the pc off for an extended period of time, when I start it up again the BSOD is back.
What exactly is this error, I have adjusted FSBT volts and upped my ram volts, is there anything I should be looking at?
I updated Intel Matrix Storage
Any help/advice would be appreceiated