NetBackup Finds Library, But Not Drives Attached using NDMP

Running NetBackup 7.1 on Windows Server 2008 R2. I have an HP StorageWorks MSL4048 tape library with 2 drives installed. These are attached with fibre to 2 fibre channel ports on the back of my NetApp FAS2240. When I run sysconfig -t and sysconfig -m on the NetApp, it shows the 2 tape drives, and the library. When I try to discover these devices in NetBackup using the storage wizard, it only finds the robotic library, and lists the 2 drives as "unused element address". I have seen this happen once before, but that was a probelm with an old NetApp that did not have tape config files for the newer LTO5 drives. This is a new NetApp that already has the HP and IBM LTO5 drive tape config files. And the NetApp detects them successfully anyway. Any ideas why NetBackup does not? We verified that ndmp is ON, and the account name and password should be good, otherwise it would detect nothing at all. I can even unplug the fibre, and run the wizard again, and it detects nothing, so I know that is all working correctly.