tapes not copyable by dd???

[Jeffrey W Percival]

I have a 6250BPI reel-to-reel tape made by the VMS backup program.  VMS
folks call it a "saveset" tape.  I can't seem to copy this tape onto a
TK50 with Ultrix.  dd appears to do the job, but when the resulting tape
is subjected to the uunet-archive program "vmsbackup", it says "end of
tape" right away.

Does anyone have any suggestions?
-- 
Jeff Percival (jwp at larry.sal.wisc.edu)