I also have the nak timeout error on my 4000/040. Worse than that, I put it into Zorro II mode and it still doesn't work. I have the clockport model incidentally - do I need to do anything besides remove the perspex cover?
Has work begun on investigating the problem? If not, do we have some idea of timescales?
Until a few weeks ago I'd wrongly assumed that the A3640 was just the upgrade card for the 4000/030, so I can see now just how big an issue this is.