DAT 72 Second tape loading problem

[Papi Reddy]

I am using DAT 72 USB tape drive, when ever script confirms for second tape, we prepare second tape and it takes fine, but for the past few days, After preparation also, Backups are not getting performed well.Few times it takes automatically.

A dialog box displays to insert a tape with name previous dates, (not the present days tape)I try to remove previous days backups from backup folder.

Any one please provide solution.

Thanks in advance.