>  If
> you did,  make sure that that the unix path to tape 
> "/dev/rmt/X" corresponds to
> a proper "tapeX" device on Windows server.

And note that Windows will sometimes change the "tapeX" device names around.
I've seen this happen during reboots, but I've also seen it happen a couple
of times for no apparent reason.

Make sure there's nothing running on the Windows server that might try and
access any tape drive it can see, like the removable storage manager
service.

                                                - Bluejay Adametz

All sunshine makes a desert. - Arabic proverb