Comment 32 for bug 510059

The solution in comment #29 worked for me in 12.04. However, one of my accounts still had problems (while other accounts on the same machine worked OK). It turned out that there was a local smb.conf file in the .smb directory of the account's home directory. I simply removed the entire .smb directory and then the global settings in /etc/samba/smb.conf had effect.

I guess you can enter the settings in comment #29 to the local file as well, but I have not tried that...