Did you power cycle the powervault 124T? Resetting it remotely does not power cycle the drive. This worked w/o any need for Backup Exec (11d sp1) reconfiguration- win 2k3 64b, direct attached scsi, lto.
Install an additional (right) magazine in PV124t
Change the enabled magazines from Left to Both in the autoloader configuration.
Power off the pv124t. (should be prompted)
Power off media server
Power on pv124t
Wait until "Ready" appears on lcd (initialization takes 3-4 minutes)
Power on media server.
Open BuE and all 16 slots should appear.