[Zope] kInterbaseDA multiple connection

[Konstantin E. Steuck]

Hello list, this is my first post here.

I'm running Zope connected to Firebird with kinterbasDA.
DB admin has recently told me that there were two active connections to 
the base under Zope user while there's only one instance of database 
adapter.

I've checked it by running netstat -a on Zope host, here's the output
--
tcp 0  0 zope_host:41838    db_host:gds_db ESTABLISHED
tcp 0  0 zope_host:41042    db_host:gds_db ESTABLISHED
--

The second connections appears short time after Zope restarts, so either 
DA or kinterbase itself seems to lose active connection.
What's more interesting is that number of connections doesn't grow 
anymore remaining at point of 2.

Has anyone encountered similar problem?

I'm using
Zope 2.7.2, python 2.3.4 on debian
kinterbasdb 3.1pre9
kinterbaseDA 2.0
Firebird 1.5

PS Sorry for my poor english :)