[slodave]

If you have four slots, they are paired up. Should have colors like Slot 1 - black/blue, Slot 2 - black/blue. That type of MB needs to run *matched* memory in each slot. At least i stick in each bank (i.e. the two black slots). If you want to fill the other two slots in each bank (the blue slots), you would (more than likely) need to fill them with two 512 sticks of RAM.

If you have tried all available configurations, it could be that the memory sucks. What brand is it? You should at least be able to take the two new 1 gig sticks and put one into each slot like above. Probably really confused you on this....