@codewiz so far I only ever saw ROMs fail on this side of a 1541. But who knows... I would also check all the chip select lines for the ROMs and VIAs. Those have to be working correctly to avoid bus conflicts. How does the data on address and data bus look?
@root42 All the signals on the bus look normal, except for D1 (pin 32 of the 6502), which looks like there's bus contention or something: