please wait until the modded ACA620 board arrived in Denmark at Demolition's place. It seems like all these "illegal instruction" effects are related to memory timing. This has been changed in the test-card that I have shipped to EAB user Demolition, and if that's successful, you will all get your fix for free.
Edit: Demolition has already done some tests and found that one of the two problems is fixed now
. We're on the right path, and I haven't run out of ideas yet ;-)