Can't backup, not enough storage

[VitaminT]

I have a HD-PNTU3.  I have been backing up flawlessly with the Buffalo Backup Utility restore tool for the past few months.  Suddenly, I couldn't backup.   I tried to do it manually but got a message saying that I didn't have enough storage.  Surely, there is a way to over write the oldest data...right?

[streerp]

I am heading towards the same problem. There is a flag in the BFBackupUtility.ini for DiffBackupMode=1 ... but nothing is documented anywhere to say what Mode 1 is and what mode one should choose to overwrite etc. As a piece of software to be supplied by a reputable company, the documentation is very poor to non existent as far as detailed usage is concerned.
I look forward to some feedback from Buffalo themselves on this.