Error upon reboot

[PK*]

System Specs:
2 x 2.6 Xeon CPU
2 x 160gb SATA Western Digital Hard Drives - RAID
2 gb pc2700 DDR Ram
Supermicro 1u case/motherboard
Windows 2003 Standard Server

Here's the problem:
The server has been experiencing very inconsistant problems upon reboot. We're receiving the all so popular "REBOOT AND SELECT PROPER BOOT DEVICE, OR INSERT BOOT MEDIA IN SLECTED BOOT DEVICE AND PRESS ANY KEY" error, but it's not happening every time the system loads up. This system is new and I can vouche that this is not anything to do with the OS since it's been present for both OS installs (XP + Win2003) since the birth of the server. The server randomly won't restart, then after a few retries it loads without a problem. Usually the problem exists only upon reboot, but last night we noticed that the system was unpingable and had crashed, when we called our datacenter for help they informed us of the current state the system was in with the above error. Since we've had this error before and usually can get past it by a few reboots, it's a tough call. Right now the box is down and we can't get it back up. We lost control of our remote card as well.

What we've tried so far:
Browsing around various forums, I notice this error is a common one, but everyone has their own situation. I've tried disabling the PXE in the bios and rearranging the boot device order. Also we've swapped the drives and the system loads fine. It's difficult to troubleshoot this problem since the machine has been so moody in the past.

Any help would be greatly appreciated. I am stumped and can really use some comments on this one. Thanks in advance.

update: Just got off the phone with our datacenter guys and they tried swapping hard drives, loading with only 1 at a time, changing boot order again, and safe mode and each and every time the new problem is that it goes to the Win2003 splash, then get a Blue Screen of Death then reboots... EVERY TIME.

urrrrrrrrrrr