Tx for advice, rebuilding kernel now. Thought that only had to add 

append="max_scsi_luns=2"

to /etc/lilo.conf and reboot get the kernel to scan for more LUNs.  

And yes, this is a test box that does have a number of security patches in it.  
The actual backup servers in use are mainly NT4 servers running Retrospect, and 
this is my old box in a corner for getting Amanda up and running to replace 
them.

Cheers de Mark @ 7tronics