Target data file already exists

Hi All.

Im getting this error:

[Minor] From: BMA@bf-backupssvr.neath-porttalbot.gov.uk "EonNAS_BFBMS01_Writer0"  Time: 08/12/2014 21:15:37
    Target data file already exists:
        "Y:\dpBackups\BFBMS01\DFMFRepository\rp_3f1a16ac55410a6c55086c5005c\D0004\F202E"

This error occurs arounf 8 times per backup each time it's a different filename. I have tried manual deleting the mentioned files but when the next backup runs, other files are mentioned.

Is my only option to delete all files and risk loosing the backups?