Samba password problem

I am having trouble with Samba 2.0.7 (on a suse 7.0 box). Everything worked fine, but it looks like I cannot change passwords. I have tried both swat and smbpasswd, but when I try to connect to the share using the new password it always returns "wrong user - password pair". The same if I try to use the old one. I am using encrypted passwords. Anyone has any idea to fix it? Tazio