I have some problems like that, i bought one 1333 memory from OCZ, and I need make the configurations to work on factory frequence, but ok, work for some days, and sometimes stops to work, I need to get out the sticks and put one by one for work again, please help us INTEL.
Check in your BIOS and look at the BOOT order , Make sure the HD with the OS on it is first inline of the Boot order . see if that helps . you see if it's not first inline than the BIOS looks at everything else thats in front of it . That takes time and can cause lock-ups.
but my lockup only happens right after logging into Windows 7 after powering it on. If the BIOS boot order is the cause of this lockup, this seems like a bug in the BIOS that needs a fix.
I made a couple of changes that seems to have stopped these lockups.
First, I uninstalled all O&O utilities. For whatever reasons, this software seems to cause me lockups. I'm a longtime user of these utilities, but stability seems to have declined in newer versions.
Secondly, I changed my BIOS setting for Command Rate from 1T to 2T. 1T appeared to work and passed the Intel memory stress test for hours, but I'm guessing there may have been an issue related to this setting that only appeared under certain circumstances. 1T is supposed to provide faster memory access than 2T.
It looks like I'm fine now.
Several hours after I had posted this, my machine locked up again. Changing the Command Rate to 2T was not the solution.
It appears my issues are related to my video cards. The screen will sometimes freeze with no activity, but my hard drive light still flickers. If I give the system enough time, sometimes my LCD panel powers off then comes back on with everything working. Windows 7 displays info about the display driver recovering in the task bar. The event viewer contains a couple of these messages: Display driver nvlddmkm stopped responding and has successfully recovered.
I have two NVIDIA GTX 470 cards running SLI. I changed the PCI latency in the BIOS from 32 to 64 and changed the Command Rate back to 1T.
Time will tell if this changes anaything.