We're having a weird problem where people's membership in certain groups isn't being taken into account. "getent group" shows the proper groups and membership information, but "id" has some confusion. "id username" shows the correct groups no matter who it's run as, but "id" run by the user sometimes has groups missing. It's always the same groups missing for the same people, but not always the same groups for all people. As a result, people who are in a group cannot even "cd" into a directory that is locked down (770) to a group they're a member of. It's quite frustrating. We have this happening on a RH9 (Fedora Legacy) box, running the latest 3.0.15pre2 package from samba.org, and an Ubuntu/hoary server running Samba 3.0.14a.
please retest against 3.0.20a