KT3 ultra with 1gb memory problem

[jsfiat]

I have a KT3 ultra board that has been working fine for 6 months. 2000xp proc, 512kb crucial pc2700 ram, raid setup, nvidia geforce 2 vid card. I ordered another stick of 512kb of the same crucial mem, and no matter what combo I try, the computer boots to safe mode with 2 sticks of memory. I tried kingston in combinations, same thing. I cannot see anything in the bios that would not allow the 2 sticks. So long as i use one stick, it works fine. No overclocking has been done, i just want more ram. Thanks for any help