Driver_irql_not_less_than_or_equal

Windows 7 has been very stable most of the time, but today I have had 2 crashes saying DRIVER_IRQL_NOT_LESS_THAN_OR_EQUAL and then just rebooted.

Does this mean I need to reinstall W7, or should I just chalk it up as a beta error?

That is often related to driver errors, so I'd try updating your graphics card drivers (as they often do it for me) to the latest ones.

I've uninstalled my nvidia drivers and just let windows update autodetect them. It seems to be working fine now, but it has only been a day. Fingers crossed that this does the trick!