Sony AIT-1 tape backup

[Brendan Simon <BrendanSimon@fastmail.fm>]

Hi,

I have a Sony AIT-1 tape backup unit (IDE) installed in a PowerMac 
running debian/testing with a 2.6.8 kernel.
I have not had much success getting it to work :(

I have made a symlink from /dev/tape to /dev/nst0

I have the following in my /etc/modules.
   ide-tape
   ide-scsi
   ide-cd
   ide-detect
   st
   scsi_mod

I only time the machine recognises the IDE tape drive is if I reboot 
with ide-tape uncommented in the modules file.  I can shows up as 
/proc/ide/hde/ -> /proc/ide/ide2/hde/

   # cat /proc/ide/hde/model
   SONY SDX-420C

   # cat /proc/ide/hde/driver
   ide-scsi version 0.92


When I initially boot I can run commands like "mt status", etc.
When I try writing to the tape it just seems to hang and then I not talk 
to the device again.
I get error messages such as:
   /dev/tape does not exist
   /dev/tape no such device or address

Any ideas what could be causing this?
Has anyone successfully used a Sony AIT-1 IDE on a Linux machine 
(PowerPC or otherwise).

Many thanks in advance for any help.
Regards,
Brendan Simon.