Hello Robertson,
a) Passwords are correct
b) User is not locked out
c) users are in the group
d) folder permission is set to 777
e) share permissions are okay.
if i do the smbclient -L localhost -U user1 -d5
everything is okay.
if i do smbclient -L localhost -U user2 -d5
i got:
SPNEGO login failed: Undetermined error
session setup failed: NT_STATUS_UNSUCCESSFUL
i think something goes wrong there..