i agree with Reagan..
San Media Server is just an another media server.
first cross verify, whether you have added the media server to master server's EMM database.
#/usr/openv/netbackup/bin/admincmd/nbemmcmd -listhosts
check if your newly added media server lists out or else add it using nbemmcmd
if this is successfull, then remove the storage units, robots, drives in the media management that are belonging to new media server.
now try re probing them from master server administration console's storage device configuration wizard, this is to ensure to make the emm clear all the stale entries and get itself clear that it has a new media server and a dedicated tape library is available for this.
if you want me to be straight forward on this, i see this as configuration issue related to EMM, so try clearing all entries and reconfigure the same