Hello,
I had a dodgy DKB Cobra accellerator card too, the exact same model as yours. What I found was that it would crash frequently but ONLY if the data cache was enabled. It may have been the instruction cache, my memory is foggy, but I think it was one of them.
What you can do is try booting into a Workbench with the command Setpatch disabled....because Setpatch actually turns on all caches (even if you disable caches by booting into Amiga Early Startup Control (the two mouse buttons upon boot).
So definitely see if turning off the caches makes a difference. If so, find out which cache it is. If this is the case in your case, then like me you'll probably want to get rid of the card (drove me nuts). I just assumed the CPU was faulty and I gave the card away. Otherwise you can use:
C:Setpatch NOCACHES (leaves caches alone)
Then use the C:CPU XXXX XXXX command immediately after Setpatch to enable specific caches of your choice. I can't recall the syntax, but just do a CPU ? in a shell window to find out the correct arguments.
