P6T Deluxe V2 + RAID woes

I just built a new system:

- 1000W Corsair Modular PSU
- P6T Deluxe V2
- i7 920
- 12GB Ram
- Dual GTX260 in SLI
- 4 640GB WD Black HDs
- 1 Blu-ray/DVD/RW/etc.
- 1 Standard DVD/RW
- 64 bit Vista Ultimate

However, I'm having intermittent problems with the RAID. I originally set up the four drives in a RAID5 configuration. However, after all of the software installations, I noticed that my performance from my HDs was dog slow. I installed the latest (Windows-version) Intel Matrix Storage Manager which told me the volume was initializing due to one of the disks being marked bad. Well, that took about 24 hours...not good.

I removed that one drive from the mix and ran some HD tests against it, which came back normal. So, I decided to go with a RAID10 setup instead...to get better performance AND to sidestep the long initialization process that occurs anytime a "dirty" shutdown occurs.

I re-installed everything (ugh!!) and boom...the first day it happened again...same drive, except this time in the RAID10 config. Now I'm thinking I better check the HW. I replaced the SATA cable, let it rebuild that volume and left for the day. When I returned, the same drive was marked degraded again. Hmmm. So, I'm thinking my next step is to swap the SATA cables on drives 3 & 4, effectively putting drive 4 in the 3's previous place and vice-versa. My reasoning is that if the problem switches to slot 3 now, then it's probably an HD issue. However, if it stays with slot 4, then it must be a motherboard issue (or a problem with the Intel Matrix Storage Software).

Any thoughts on other culprits? Oh yeah, forgot to mention that I originally purchased a 750W Corsair to run the whole unit, but thought that it was probably an under-powered disk originally. Thus I went with the 1000W, but am having the same issues.

Suggestions? Ramblings? I'm open to any input.

Thanks for the help!