Got my replacement RAM (XMS2 6400 C5)
With BIOS settings at auto (1.8V, 5-5-5-15 I think), it produced a few errors in Test 7. I didn't see this is an indication the RAM was faulty, however.
With the FSB and the RAM at 333 (1:1 4-4-4-12), VCORE@1.35, VDIMM@2, it appears stable, fast, and...