CompuServe Messages

Hello. I've written messages over every major CBM forum, so I'll try this one too. I'm having trouble with my XT Bridgeboard. When I open a PC window, it always (well, except for 2 times) gives me a E000 Optional ROM Checksum Error. When I change the prefs RAM setting to D000, it gives the same error, but with D000 as the address. When I select A000, I get no error. However, regardless of the setting, I never get the Janus Handler v2.20 Found prompt (well, almost never; it has appeared twice). What is wrong? I've moved the board to the other bridge slot, I've re-installed the PC Bench three times, and it still gives the error. Nonetheless, the board still runs IBM software, but this error shouldn't occur (and I believe it interferes with my not being able to use the PCDisk program for virtual drives.) My motherboard is rev 4.1, and I don't have anything else in the other slots. What gives?