[Rhyisa]

Update:

Turns out it was memory sticks. I had two older 512MB stick in my two other slots. Took them out, and presto, working EQ!!

I suspect that:

1. They are old and damaged
2. That the memory timings are different between the 1GB's (2) and the 512's

I'm thinking the later. Timings can account for the problems. Very strange. But I really don't know, just that they are out and I'm playing!