Screen Dump from Cold Boot Win7- WD Raptor RAID 0

Recently installed a RAID 0 configuration of my desktop.
i780 CPU
6 GB RAM
Rampage 3 Gene MO
2x WD Raptors - 300gb
5850 ATI video card

Stange symptoms:

Issue one: Some times when I copy data from one drive to the next (I have 2 more segates in my machine) where I am copying a few hundred gigs the process goes to "sleep" it seems and forces me to reboot.

issue two: from cold boot I have a 50/50 chance that I get a screen dump on my dispaly with a reboot. It sometimes reaches the logon screen and sometimes not.
During the second reboot I see the bios initialising all devices quickly but one, one of the WD HDDs, taking some 10 to 20 seconds before moving on. Once this happens all works just fine and I can use the PC all day just fine.

Is my problem memory?
Is my problem the HDD?
Is it something else?
Any whay to check?