I think the issue is related to the way "autoconfig" works: even a small portion of memory (like the ones reserved from the Buddha) can fragment the autoconfig space, resulting in no sufficient room for the 4Mb RAM card.
Use only 2Mb on the expansion card and use the "powerful" 4Mb on the A2630 accelerator.
If you want more RAM in your system, go for a better accelerator or a DKB 3128 or that other one who accepts 64Mb (don't remember the name right now).