Postgres 8.4 Segfault on xpath

Hi,

I am trying to migrate a 32-Bit server running Postgres 8.3.1 to another
machine running 8.4.0 on 64-bit. I have compiled Postgres 8.4.2 on a
Debian Leeny 64-Bit System and getting constantly Segmentation Faults
(Terminated Postgres Server by Signal 11) when a specific function,
which uses xpath is executed. When i execute the function with the xpath
statement alone in psql, it is working as expected. But if i execute a
cascaded function, whose child is executing the function, which uses the
xpath statement, i get the segfault.

I tried postgres 8.4.0 and 8.4.2 self compiled with  elf compiled
contrib directory,  tried Debians 8.4 backport package with the 8.4
contrib package and all do the same: Segfault and terminated by Signal
11 :-(

I just compiled Postgres 8.3.1 on the new 64-Bit rig and it is running
fine...
But my boss wants me to move to 8.4, so i am a bit lost.

Kind regards,

Frank Jansen

The function:

feedimport.is_blacklisted(p_external_broker_id,xpath_string(l_xml_item,'/immobilie/verwaltung_techn/objektnr_extern'))