catch a T4000s)
+ Set *some* kind of error at EOM if we're in fixed mode and have pending errs.
Do not clear the ERR_PENDING bit if more buffers are queued.
+ Release the start_ccb in this case also, else we hang forever on rewinding.
+ Any kind of error for load to BOT in samount should then cause an attempt
to use REWIND to come back to BOT. Do the initial load command quietly.
+ In samount, if we succeed, set the relative position markers.