NW65 SP5 + GW65 SP6 + BE 9.1 installation

I lost the SYS volume due to disk failure and was forced to re-install SYS from scratch
(The required backup tapes had been nightly rotated through a lady's handbag with a magnetic clasp)
Yippeee !
OK so I then recreated each of the users in NDS and re-associated with users in existing GW installation on MAIL volume
All seems fine and works OK until we try to backup
Using GWTSA the GW system is visible in BE 9.1 and is selectable in the backup job
However when the scheduled job runs the log reports:
##WRN##Device "SERVER.GroupWise System:" does not contain any objects to backup.
##WRN##All selections related to "SERVER.GroupWise System:" will be skipped.
and consequently none of the GW system is backed up

Any ideas to resolve would be much appreciated, but preferably not involving the use of TSAFS.
I never seem to be able to get a satisfactory installation of TSAFS and there's really no adequate confirmation that TSAFSGW is enabled or whether BE has in fact backed up the databases.
Anyway, in this case TSAFS doesn't seem to have been installed during the re-installation !

My current solution is to unload all GW agents using CRON prior to the backup
Then backup the entire file system including the MAIL volume and then reload GW
Pretty amateurish I know, but at least it gives me a backup with integrity !

Tried re-associating and re-installing BE a couple of times but no joy
It seems BE just cant see the contents of the GW system
So what would the experts do ?