ntbackup

i used the native ntbackup program for windows nt.
and for some reason the backup doesnt work properly anymore, it takes 3 tapes now to finish the backup with hardware compression, before it only uses one tape. the size of hard haven’t been change, and i backup to drives plus the EXCHANGE DS & IS…..i am just wondering if this will fix my problem if i upgrade the tape drive from dds-2 to dds-4…..thanks