BL>           I think there may be something wrong with UNZIPDOS.EXE. I
 BL> tried to freq it yesterday, and it jammed up in the first 8096 bytes
 BL> after all sorts of Telix errors with bad packets, bad CRCs and finally
 BL> timeouts.

 BL>   It did the same when I tried it again this morning...

unzipdos.exe is uncompressed.  Hence you will get about 2:1 compression 
on it, so it will be transferred by the modems at 28800 bps.  IOW this
is very high speed transfer.  Your system obviously can't handle that.
Run it from Telix under vanilla dos and it should work fine.  If that
doesn't work, change the baud rate to 9600 and try again.  BFN.
@EOT:

--- Mksmsg