I don't see any listings for the 3000, but the 5000 ("DS5K") appears to be included in the latest Compatibility Matrix.
NetBackup (tm) 6.x Snapshot Client (Advanced Client) OS, Arrays and Database Agent Compatibility (Updated March 8 2010)
http://support.veritas.com/docs/279042
All the "DS5K" listings with the "IBM_StorageManager_FlashCopy" provider appear to have 6.5.4 listed as the start of support, if I'm reading it right.
Good luck!