I had seen your problem befor by a friend. He also have the same problems, but with a Blizzard 1260 and 4xEIDE'99 IDE controller.
The problem is the revision of your A1200 motherboard.
The best revision is 1D1. I have one of those today from a store.
If I disconnected the B1260, the board will work with IDE controller. The same when I disconnected the IDE controller.
Look for more info:
http://www.eyetech.co.uk/addbar.php?Address=/PRODUCT/PAMAC/AMIGA002.HTM
