Milter-greylist

Hi,

we are running milter-greylist-4.2.3 on Solaris 10 x86, it works great 
so far, but I'm a little concerned by its memory consumption. Right 
after starting the service it uses < 30Mb of RAM but after running it 
about 48h it uses already ~1Gb of RAM.

Is this normal?
Is there something that could be done to limit the memory consumption?

Here is some additional information:

The greylist.db is about 14Mb and gets dumped every 15 minutes.

We used the following configure option for building the package.
./configure --enable-dnsrbl --sysconfdir=/etc/mail --with-user=smmsp

The milter is used together with sendmail-8.14.4 and linked against its 
libmilter.

I hope someone can help us with this issue, and please let me non if 
there is more information that I can provide...

Thanks
   Didi