>Well I just called the shop after waiting patiently for 1.75 days.
>
>Seems their tests are indicating memory (access or addressing) problems and the issue persists even with replacement RAM installed.
>So the prime suspects now are:
>1) motherboard L2 cache (or something else on MB);
>2) CPU cache (an AMD X2 - 4400+ socket 939 installed new within 6 months).
>
>Here's the hooker...
>The motherboard is discontinued and cannot be ordered (ASUS A8V Deluxe) so I'm told that if it turns out to be the motherboard it has to go through the "RMA" process which sounds like it could take weeks!
>They seem to be oblivious that it is my WORK SYSTEM.
>
>I asked about an equivalent replacement and they are hedging on the issue.
>Their main concern is that the RAIDed C: will be clobbered by any change in controller (I used the Promise controller on the ASUS (it has 2, VIA as well)).
>
>Lessons learned:
>
>1) WHen buying a new PC, buy an extra motherboard;
>2) Don't bother with RAID, at least for C:. I gets you no benefit and lots of trouble.
>
>cheers

Spare mobo is an excellent and often overlooked tactic - they're so cheap. RAID 1 has its place, especially for low- to medium servers or other places where data loss from one failed drive would be expensive.

According to http://www.ocworkbench.com/2004/asus/a8vdeluxe/g1.htm , that mobo has a Promise 20378 controller. If you google "promise 20378 controller" you get lots of hits - it looks like lots of mobos use it. Maybe you could ask if there is another machine with one of these that could be used to copy your data to another (maybe single/standard SATA or PATA) disk. Or, failing that, just long enough to "break" the mirror so you can use either drive standalone.

A standalone Promise FastTrak TX2300 controller may be compatible. You could ask to borrow one so you could put your drives in another system to see if it works. To buy one looks like a little over $80 OEM ( http://www.cdw.ca/shop/search/results.aspx?key=fasttrak+tx2300&sr=1&platform=all&x=0&y=0 )