incorrect media found in drive index 0 when running duplication on Netbackup 7.1.0.3

I encountered this when running duplication. I normally use 6 media. The 4 tapes always freeze.

Error bptm(pid=4740) incorrect media found in drive index 0, expected 127FAO, found DT3CBO, FREEZING 127FAO
9/7/2012 1:47:51 AM - current media 127FAO complete, requesting next resource Any
9/7/2012 1:48:42 AM - Info bptm(pid=4740) EXITING with status 96 <----------       

I tried to unfreeze the media affected, and expired again and ran duplication job. Still my duplication job is partially successful.

I'm thinkng that the media affected is defective and I will try to use new one. But any inputs/solution to my problem is much appreciated.

Thanks.