Over here on the French side is a user that reported the same error.
http://forums.contribs.org/index.php/topic,38503.0.htmlUsing Google translation (I am sorry but I don't know french) it looks like that user fixed it by creating a user with the proper access.
FOR TESTING PURPOSES ONLY
1. Create a new share that is a folder on C:\ on the windows machine, lets call it backup. You would now have a folder that looks like this C:\backup.
2. Share the folder with Windows file sharing tab with the share name of
backup click the
allow network user to change my files box.
3. Create a new administrative user in windows with the user name of
backup and a password of
backup14. Set the SME backup routine to point to the new share and use the
backup user name and the password of
backup15. Pour a little Snake Oil on the top of the server and massage gently
.
6. Set a backup to run in 5 minutes and see what happens.
**Be sure to delete your shares and account after this test if you do not wish to keep them.
If your windows share is in the Documents and Settings area of the Windows file system and it is created on a different user then the user used for the backup, The backup user may not have access rights to the directory.