SCO/mountain streamer: cannot read tapes

[Roland Bergler]

I got trouble reading tapes written on other unix-machines on my 
Mountain filesave 150 with QIC-02 interface with SCO-unix 3.2.v2.0.
The tapes were written on a sun tape drive using tar, and can be
read on virtually any othr unix systems, includeing SCO with SCSI streamer.
(i didn't try other mountain / SCO-environments, for i dont have access to 
any other except mine)
I tried reading the tape with tar, dd and even cat </dev/rct0, but all
i get is Read I/O error (from dd and tar). tapes are writte in 150MB
and 60MB formats, doesnt't work with either.
can anybody help??
roland