Random RAID failure

I purchased my Aurora system in late october 2009, and finally got it in late november 2009. However I have this persistent problem where my computer would randomly freezes.

1) The RAID would randomly drop one or both of my hard drives (the problem occurs in both RAID 0 and RAID 1 configuration) on a daily basis, when that happens Windows would totally "freezes" - whether the computer is idle or in use. After powering down and back up, everything works fine (I can reset the RAID status back to 'normal') for a while and the problem would reoccur again.

2) I'm called DELL support and we've replaced one of my HDD which showed as failed in the DELL Diagnostic Tools. After replacing the drive the "random freeze" problem still continues. Note that they didn't send me a replacement drive with a model that matches the other model, even though when I spoke with the tech he clearly agreed that both drives should be of the same model since this is a RAID setup (DPS# 122219999).

3) After some weeks of googling and testing, I've isolated the problem to be with the Intel Rapid Storage Technology software: version 8.9 and higher, including the latest 9.5.6.1001, would cause the random freeze and drive drop out from the RAID. I installed the old version 8.8.0.1009 and have been problem-free for over 2 weeks now (vs. daily or every other day RAID failure).

4) Further googling would suggest that to work properly in a RAID configuration, one should use "RAID-Enabled" drives like the WD RE3/RE4. Unfortunately my system only came with non-RE drives from WD, which I was painfully disappointed (why would DELL/Alienware sell me a RAID configuration and not provide RAID-enabled or at least RAID-compatible drives???)

5) After some more googling it would appear that if I can enable "TLER" capability on those WD drives using the infamous "WDTLER" tool then the problem ought to go away since the drive would become RAID-compatible. Unfortunately after some testings, this appears to be feasible on the original Seagate HDD that came with my system (attached to SATA 1), but not on the replacement WD drive that was shipped earier (SATA 0).

Questions to this forum:

a) does anyone have this problem, and if so how did you resolve it?

b) although I could possibly stick with the old Intel Matrix Storage Manager 8.8 for a while, it is likely that sooner or later I would need to move to the new Intel Rapid Storage Technology software (be it for bugs or compatibily/supportability purpose), has anyone been successful at enabling TLER on their hard drives when used in a RAID configuration?

c) how can I get DELL to re-send me 2 identical drives that support enabling TLER to replace my current ones?

System Configuration:
Alienware Aurora, BIOS A04
Core i7 940, 9GB RAM, 2 x 500GB RAID 0 (currently setup as RAID 1)
Windows 7 Ultimate
Intel(R) ICH8R/ICH9R/ICH10R/DO/PCH SATA RAID Controller (BIOS is set to RAID mode - not AHCI)
Dual NVIDIA GeForce GTS 240
SATA drives = PLDS DVD+/-RW DH-2AAS, WDC WD5000AAKS-75V0A0 (S/N: WD-WMAWF1040311, F/W: 05.01D05), Seagate ST3500418AS (S/N: 9VM4M0GR F/W: CC44)