Mabye this is the solution:
Throw all 'Users' away and make these two users:
pcguest, nopassword, 586, 99,Samba Guest, sys:, noshell
root, password, 0, 0, , , sys:
Throw all 'Groups' away and make this group:
guest, 99, pcguest
Go to 'Access' en click on '$' en change it in 'allow'.