HTAnchors lifetime

Hi all.
I'm dealing with a problem about HTAnchors.
My application is a non interactive one; it must be running in the background for an indefinite time, like a deamon process does. 
It has the need to invoke a huge amount of CGI URIs (most of the times we have different query strings but same addresses and paths). 
I can see that the size of the hash table provided by libwww, containing the HTAnchor objets, is growing fast while requests are serviced; and the amount of memory owned by the process becomes greater and greater.
I'd like to know how to limit the growth of the HTAnchor table.
I have read that an Anchor lives (in most cases) as long as the entire application. 
Is this really unavoidable?
What is meant by "in most cases"? 
 
Anybody can help me please?    
Thanks.

Cesare Pietra
Mobile Applications Area
NETikos S.p.A.
Via Matteucci 34/B
56124 PISA
Tel.: + 39 050 968526
Fax: + 39 050 968525
e-mail:  cesare.pietra@netikos.com
Internet: www.netikos.com