System Log is logging row number -1 is out of range 0..-1

version: "PostgreSQL 8.3.8 on i386-apple-darwin8.11.1, compiled by GCC
i686-apple-darwin8-gcc-4.0.1 (GCC) 4.0.1 (Apple Computer, Inc. build
5370)"

We are using custom plugin to connect to postgresql.
We reviewed OS (OS X 10.6.2 2.26 GHz Quad-Core Intel Xeon Meomory 6
GB) system log and noticed that the following lines are repeated in
the log all day...(This log records NOTICE from sql as well)

=========
Feb 17 20:43:25 LLX-4DA-2 [0x0-0xfd8fd8].com.4d.4d[73523]: row number
-1 is out of range 0..-1
Feb 17 20:44:45: --- last message repeated 57 times ---
==========

"4d" is a 32 bit application (programming language + database engine
which we don't use) we use to connect postgres. We are using custom
plugin written in C by 3rd party to connect to postgres.
I reviewed postgresql's log and this is not logged... however, when I
google this error message, I saw once back in 2005 there was a
discussion about it therefore I thought this might be then related to
postgresql and hope that someone could direct me to right direction to
correct this error...

Thank you very much for your time in advance.