Tape Lib with mutiple tape drives

Just started here and have been working on getting backups back to working correctly.  One issue I am seeing is we have a Overland Neo2000 lib with two HP Ultrium 4-Scsi LTO 4 drives.  I can not get both drives to run at the same time, I have set the drives to each manage 2 of the 4 partitions that are on the lib.  I have jobs set to run to different partitions but only one job runs.  This is just one issue I am working on but any help would be great.

Thanks

And may I add that the interface on Backupexec 2012 is not user friendly as the interface in 2010 seems very limited in what you can do.