> You can add fprintf(stderr, ...) lines into util.c to debug things: That's what I did, on rsync-2.6.3pre2 and I got : Lookup of `root' returned 0 Lookup of `testuser' failed By the way, I upgraded to samba-3.0.7, since I saw in the list of bug fixes "winbind failure to return user entries under certain conditions", without improvement. I still don't see anything in the winbind log.