Sometimes it happens that Microsoft Data Protection Manager 2007, 2010 and 2012 mark a tape as ‘suspect’. Normally this should happen when 2 different tapes have the same barcode… If you do know that there are not 2 identically labeled tapes in your library then you can run the following from an elevated command shell on your DPM server:
DPM 2012:
osql -E -S localhost\MSDPM2012 -d DPMDB -Q "UPDATE tbl_MM_ArchiveMedia SET IsSuspect = 0"
DPM 2010:
osql -E -S localhost\MSDPM2010 -d DPMDB -Q "UPDATE tbl_MM_ArchiveMedia SET IsSuspect = 0"
DPM 2007:
osql -E -S localhost\MS$DPM2007$ -d DPMDB -Q "UPDATE tbl_MM_ArchiveMedia SET IsSuspect = 0"
After that rescan/refresh your library information in your DPM console and your tape should no longer be labeled as suspect. Sometimes you’ll need to remove the tape from your library and insert it again or move it to the drive and back again.