ipmon log rotation

Hello,
Trying to figure this one out, I've got ipfilter running on fbsd 5.1. In
my rc.conf file i have:
ipmon_flags="-Davn /var/log/firewall.log"
then i followed the ipmon example for log rotation given in the rc.conf man
page and added the following one line to /etc/newsyslog.conf:
/var/log/firewall.log 600 3 100 * Z /var/run/ipmon.pid
I'm having two problems, firstly, the log is in fact being written but when
newsyslog rotates the log file ipmon continues to write to firewall.log.0
which i am assuming is the previous log file and the new log fille,
firewall.log has only that newsyslog rotated it. The second problem and this
might be related to the first is that newsyslog is not compressing these
logs.
Thanks.
Dave.