Ouch, that doesn't sound too good!
I'm not sure if I've read you right, I got the impression that you did the following:
- Tested each stick of
RAM in one of the slot and everything works OK?
- Tested each stick of
RAM in another slot and you start having problems?
You can also test the memory itself by using memtest (if you have a spare floppy disk or cdr using Nero):
Memtest86 - Memory Diagnostic Page
EDIT: Correction, Bugsey - the good lil rabbit that he is just pointed out that you have already done a memtest? If so, can we just rule out one more thing before you send your mb back? Can you give me the details of everything see see on the stickly label on each of your
RAM? Also the make and model of your mb?