When you map a drive or browse computers in your workgroup, you might see invalid password errors. If you see these errors, check whether the /var/smb/smbpasswd file includes information for the appropriate users.
Also, ensure that the pam_smb_passwd.so.1 entry is in the /etc/pam.d/other file and that you use the passwd command to set your password.
For more information, see How to Configure the SMB Server in Workgroup Mode.