Cleanup after backups keep failing!

The way I have our backups is every friday it does a differential, and every other day (Sun-Thur) it does incrementals.

So after each backup I tell it I want to remove backups older than 7 days, but I want to consolidate the backups.

This backup is to a FTP server. Why do I keep running into this problem? Is there another way I should be doing FTP backups? If you are wondering about the full, I do a manual full at the beginning and put it on the FTP by hand (like going to the site, moving it to a USB drive and bringing it back to work kind of thing)

This is Windows Server 2008 R2 servers

Type: Information
Date and time: 2/14/2011 10:30:24 PM
Backup plan: Backup 2/6/2011 9:43:01 PM
Task: Cleanup (custom scheme: after backup)
Code: 262,147(0x40003)
Module: 4
Owner: administrator@********
Message:
Error occurred while writing the file.
Additional info:
--------------------
Error code: 3
Module: 4
LineInfo: e79eb3cc44c3b263
Fields: $module : C:\Program Files (x86)\Acronis\BackupAndRecovery\DiskBundle.dll
Message: Error occurred while writing the file.