Listener Logging NNC 00406

Every time I connect to my database, the listener logs NNC-00406 errors:

NNC-00406: name "LISTENER_hostname" does not exist

The connection seems to work okay. The listener is called simply LISTENER.

ie.

LISTENER =
    (ADDRESS = ... blah

and

SID_LIST_LISTENER =
 (SID_LIST = ...blah

in the Listener.ora file.

This does not seem to be a serious error - the only problem is that the log file quickly gets huge and has to be regularly purged. But is there something more serious wrong and how can I fix it?

Any advice gratefully received.

Many thanks,

• Bill.