You can't do one stick at a time if it's a RAMBUS mobo.
Is that an 8200 that uses RAMBUS memory??? If so, you have to have a dummy in the 2nd slot and a DIMM in the first slot followed by a DIMM in the third slot and a dummy in the 4th slot.
Make sure you have it installed as above and SEATED correctly.
First, the most frequent rules for RAMBUS in Pentium 4 systems are:
1. RAMBUS must installed in exact matched pairs. (There are some deviations
from exact, but this is close enough.)
2. Any RAMBUS memory socket not filled with a memory module MUST have a
continuity module installed.
3. You must not mix ECC & non-ECC memory.
So... You can install either a matched pair + 2 dummy modules or two matched pairs.