I'm having the same problem. I can copy file from my Vista box to my NASLite box no problem but the Vista backup utility gives the above errors.
I found this which may be of interest:
http://lists.samba.org/archive/samba-technical/2007-January/051318.html
And this:
http://blogs.technet.com/filecab/pages/file-backup-in-windows-vista-faq.aspx
Quote:
I’m trying to back up to a NAS device, but it’s not working. How can I fix this?
First, make sure the share on the NAS device is configured correctly using our blog post on backing up to network shares. Even with the share set up correctly, there might be issues in the NAS device’s file sharing implementation that prevent Backup from using the device as a target, particularly if it is a Linux-based device running an older version of the SAMBA file sharing software. We made a number of code changes in Backup to work around these bugs in SAMBA, but we could not do this for every NAS device. We recommend contacting the device’s vendor to obtain an upgrade to Samba 3.x. This version works better with Windows Vista than previous versions. And you will not have any protocol-related problems backing up to a network share on a Windows Vista PC.
which indicates it may be a problem with the version of SAMBA perhaps. Which version does NASLite use?