Weird memory issues in new system

[gobucks]

Well, I've been trying to get my new system up and running for weeks now, and it's finally working, kinda. I used to have PQI DDR500 (1GB Dual Channel) and it worked on my old mobo, the A8N-SLI, but i returned that and with the new mobo, windows kept crashing with memory errors. So I emailed chaintech about the problem, and they said that PQI was not validated, and was the likely culprit. This was further confirmed when I put some generic infineon memory (512MB dual channel) into it, and the problems went away. So I ordered a GB kit of Corsair Value RAM, since i read good things and got a sweet deal on it, and returned the PQI to newegg. Well, I just got the new ram today, and I'm having the same problems, at least in dual channel. Unlike the PQI, it worked fine with either stick by itself, but when both were put in, it kept crashing. I tried relaxing timings and upping voltage, but nothing helped. Finally, for some reason, i decided to try putting the sticks into the opposite matched pair, DIMM slots 2 and 3 (as opposed to 0 and 1). For some reason, that works, and is now stable. I even got it to work in 1T timings! My questions are 1) Does anyone have any ideas as to what could be causing this? My suspicion is the BIOS, but I'm not sure. 2) Does using the other set of DIMM slots bring any penalties? Can I still overclock, and will the timings work the same? If so, I guess I'm not worried too much, but it still kinda bugs me that I can't figure out why it's doing that. If what I'm doing won't hurt anything, I'll probably keep doing it till there is a revision or bios fix that I can get.