Floating point exception

Sometimes PSQL 6.4.2 backend reports the following:

ERROR:  floating point exception! The last floating point operation either
exceeded legal ranges or was a divide by zero

even though I have no float typed attributes in any of my tables.

Do you have any idea about the problem?

            Thanks

--------------------------------------------------------------------------------
Sebestyén Zoltán <szoli@netvisor.hu>    I'm believing that the Holy Spirit is
                    gonna allow the hand, and the foot, and
MAKE INSTALL NOT WAR            the mouth, just to begin to speak, and
                                        to minister, and to heal coordinated by
                    the head.

I use UNIX because reboots are for hardware upgrades.

           -- Waiting for FreeBSD 3.1, not Godot --