If you have followed some instructions on setting up Gentoo and eventually have trouble with samba, I reckon its because your /etc/samba/smb.conf file is bloated with a hole load of unnecessary code.
It just needs to look like this:
workgroup = MSHOME
security = user
local master = yes
valid users = %S
read only = no
browseable = no
Nice simple and secure. Allowing users to login to their home directories.