Jobs go straight to "Queued" will not run

I have just installed backup Exec 12d on a Win 2003 SBS server.

The Quantum DAT 72 drive is mounted fine in Windows Device Manager and within Backup Exec (although for some reason backup Exec sees two drives.)

All looks good until I try to run a backup job. It flickers into life then goes to Queued.

I can get an inventory job to look as if it is running - but hours later it hasn't done anything.

Any help would be much appreciated,