Hi,
Can you try it with an "older" ROM (possibly 1.3 - 3.1)? As i know You can do this with a software (don't have to disassemble anything).
Sorry! I know that it is not te best solution, but we can't test it on all the possible HW.
The SDK we use are comes from the A500 era. Amigas (HW, kick, accel..) comes after that should be backward compatible but (sometimes) that's not the case. :S