According to the DP 6.1x device support matrix
http://support.openview.hp.com/selfsolve/document/KM718727
pg 42
AES encryption is not supported for the TS3200 tape library
I looked at IBM drives individually, pp 9-11, and it appears that only these drives support AES encryption
IBM Ultrium TS1040 Ultrium-4 with AES Encryption Support
IBM TS2240 Half Height LTO Gen 4 Tape Drive (SAS) with AES Encryption Support
IBM Ultrium TS2340 Ultrium 4 with AES Encryption Support
as you can see, no mention of Ultrium 5
DP 6.11 is also well out of support