Expireover goes through the active file and tries to remove old entries
of overchan records from the spool. If now a group exists, that is new
i.e. that exists in active, but for which no articles have been received, 
then there is no spool dir for that group. Expireover tries to make
a lock file in the directory, which fails, so it prints the above message.

See also #4.19, #6.30, #7.21

Some parts © 2009 Advameg, Inc.