Backend terminated abnormally

Hello,

I not sure if I have got the right person for this but if you could help me it would be extremely helpful;

The problem is with the following query,

select l.s # p.ss from LSEG_TBL l, LSEG_TBL1 p;

when I try to execute this intersection on the tables that are in the regression queries the following message is printed to the screen,

I created two tables with the exact lseg coordinates in both to see what happened and also with disimilar lseg points so that there was lines intersecting,
and recieved the same message

pgReadData() --backend closed the channel unexpectedly.

This problem means the backend terminated abnormally
before or while processing the request

We have lost the connection to the backend, so further processing is impossible.
Terminating.

Please could give me some pointers as to where I could look or if necesarry download any patches to fix it.

I am running Redhat 5.2 on an i486-pc-linux-gnu
version of postgres is 6.5.2
version of gcc is 2.7.2.3

Thank you in advance.

Nick O'Malley nicks(dot)emails(at)ic24(dot)net