While I didn't gather enough information for a viable bug report yet, it seems I can't upgrade my old Samba 2 installations... (Which I would like to do, as communication between MacOS X clients and Samba 2 serves seems to be broken - uploads, especially, tend to time out or hang the finder on the client, while downloads are usually just abysmally slow.)
Unfortunately, Samba 3 makes problems with OS/2 clients (and I still have an OS/2 Warp 4 box here I use quite often) - obviously it now contains some sort of incomplete support for OS/2 extended attributes which can not be disabled in the server, and the OS/2 client will produce various access errors, depending on what it (or the user) is trying to do...
So, I'm keeping Samba 2 for Windows and OS/2 and NFS for the *NIX systems (including OSX) for now.
Unfortunately, Samba 3 makes problems with OS/2 clients (and I still have an OS/2 Warp 4 box here I use quite often) - obviously it now contains some sort of incomplete support for OS/2 extended attributes which can not be disabled in the server, and the OS/2 client will produce various access errors, depending on what it (or the user) is trying to do...
So, I'm keeping Samba 2 for Windows and OS/2 and NFS for the *NIX systems (including OSX) for now.