When you issue the "Mount xxn:" command, it makes no reference to the drive at that time, so no error means nothing. It doesn't reference the drive until you ask for a transfer of some kind.
I agree with Spaceman, I wouldn't trust the acitve terminator, I'd go for one of those liddle biddy ones that only terminate the top address bits.
BW, did you check that Cybertools (or whatever it is) has got "last device" set to at least 4?
tony