The Red Hat RPM of Samba 3.0 doesn't create a symlink from libnss_winbind.so to libnss_winbind.so.2. This prevents winbind users from being found by the various get*ent functions. After creating the link manually, the problem is solved. This should be added to the RPM or to the Makefile.
Oops... I just noticed this has been fixed this morning...
already fixed in cvs and new RPMS uploaded (3.0.0-2). This was done yesterday.
sorry for the same, cleaning up the database to prevent unecessary reopens of bugs.
database cleanup