flood in logs

hi,

i''m getting a lot of warning lines in log file,  they appears as
follows:

2008-10-10 12:11:49.976 CEST g@g 5696 127.0.0.1(46403) WARNING:
unrecognized node type: 742
2008-10-10 12:11:49.987 CEST g@g 5696 127.0.0.1(46403) WARNING:
unrecognized node type: 742
2008-10-10 12:11:50.004 CEST g@g 5696 127.0.0.1(46403) WARNING:
unrecognized node type: 742
2008-10-10 12:11:50.015 CEST g@g 5696 127.0.0.1(46403) WARNING:
unrecognized node type: 742
2008-10-10 12:11:50.460 CEST g@g 5696 127.0.0.1(46403) WARNING:
unrecognized node type: 742
2008-10-10 12:11:50.471 CEST g@g 5696 127.0.0.1(46403) WARNING:
unrecognized node type: 742
2008-10-10 12:11:50.490 CEST g@g 5696 127.0.0.1(46403) WARNING:
unrecognized node type: 742
2008-10-10 12:11:50.504 CEST g@g 5696 127.0.0.1(46403) WARNING:
unrecognized node type: 742

from 2M lines only 200K was different then these

have you got any idea where do they come from? and how can i stop
them? i was trying to solve the problem, but with no result

i'm using:
    Ubuntu 8.04.1
    PostgreSQL 8.3.3 on x86_64-pc-linux-gnu, compiled by GCC cc (GCC)
4.2.3 (Ubuntu 4.2.3-2ubuntu7)
    pgbouncer version 1.2.3

Thanks in advance,

Reagards,

Sebastian Pawlowski