This may sound silly, but do you have 3.1 roms installed?
Try removing all the ZIP memory from the motherboard and only use 2MB chip ram + accelerator + accelerator's on-board simm memory.
Newstyle expansions for A3000 such as Prometheus, Cyberstorms, Mediator, etc. should all work fine with Dmac 2 and Ramsey 4. AFAIK, Dmac and Ramsey need upgrade only for a bit more stable usage of A3640 card due to some conflicts with ZIP memory and the on-board SCSI controller.
I've heard stories that Phase 5 never tested their A3000 compatible accelerators with newest Dmac and Ramsey chips, but only old ones, thus causing incompatibilities in some cases when the users have upgraded chips in their systems. Even in manuals they specifically stated that with A3000 usage, Dmac 2 and Ramsey 4 are recommended...this could be due to the rarity of Dmac 4 chip (Ramsey 7 is not so rare, as it was produced in larger quantities due to its necessity in A4000T).