Samba logs for both IP address and Hostname

[Dominique Brazziel <dbrazziel@snet.net>]

I have a home LAN with 2 WinXP and 2 Win98 machines,
and 
see log files generated for both IP address and
hostnames
of the Windows machines.  I only want the log.hostname
format, and have specified the default for logfile in
the 
smb.conf:

/var/log/samba/log.%m

Is this a bug?  If not, then why are the log.IPaddr
files there?