Comment #7 on issue 231 by esoteric...@gmail.com: SASL authentication not working on reboot
http://code.google.com/p/memcached/issues/detail?id=231
Another note: in the workaround of changing the group of /etc/sasldb2, the group must be the primary group for the Memcached user (i.e. the one listed in /etc/passwd).