@zx6r6:
Which one of those on Aminet did you do? I think
this is the only one that will work more or less ok as it has circuitry to avoid double-clocking the E-clock plus some correction of the DTACK-signal.
The other ones just passes all the signals from the 14MHz 68000 unmodified to the motherboard, including a double-clocked E-clock which makes the 8520 chips screw up some of their timings, which you seem to have seen the results of.
/Patrik