Finally, a clue! Upgraded from the stock smbd version from the 5.4 iso to 3.0.33-3.28.el5, and now an error message makes it into /var/log/messages: May 24 15:29:12 xyz smbd[2674]: [2010/05/24 15:29:12, 0] lib/messages.c:message_init(132) May 24 15:29:12 xyz smbd[2674]: ERROR: Failed to initialise messages database Anyone know what that's about? It's only from the invocation attempts that dependably fail (like "service smb start"), not from those (like "smbd -D") that dependably work. Regards, Whit