PostgreSQL service terminated by query

I'm hoping I can get some info on a query which terminates my PostgreSQL
service.
The query is a relatively simple PostGIS query:

SELECT en.gid, ST_LENGTH(en.geom) total_length,
(ST_DUMP(ST_INTERSECTION(en.geom, evc.geom))).geom::geometry(Linestring,
3111) geom
FROM en, evc
WHERE ST_INTERSECTS(en.geom, evc.geom) AND en.gid =355620;

I've run this query successfully with en.gid equal to other gid values
(gid is the table PK). The success seems rather haphazard though so I'd
like to find out the underlying issue. The above feature with gid = 355620
is valid and appears no different from other features which have worked.
The log text when the service crashes is:

2013-03-26 15:49:10 EST LOG: database system was interrupted; last known
up at 2013-03-26 15:42:29 EST
2013-03-26 15:49:10 EST LOG: database system was not properly shut down;
automatic recovery in progress
2013-03-26 15:49:10 EST LOG: record with zero length at 9A/E7AAD938
2013-03-26 15:49:10 EST LOG: redo is not required
2013-03-26 15:49:10 EST LOG: database system is ready to accept
connections
2013-03-26 15:49:10 EST LOG: autovacuum launcher started
2013-03-26 15:49:55 EST LOG: server process (PID 3536) was terminated by
exception 0xC0000005
2013-03-26 15:49:55 EST HINT: See C include file "ntstatus.h" for a
description of the hexadecimal value.
2013-03-26 15:49:55 EST LOG: terminating any other active server
processes
2013-03-26 15:49:55 EST WARNING: terminating connection because of crash
of another server process
2013-03-26 15:49:55 EST DETAIL: The postmaster has commanded this server
process to roll back the current transaction and exit, because another
server process exited abnormally and possibly corrupted shared memory.
2013-03-26 15:49:55 EST HINT: In a moment you should be able to reconnect
to the database and repeat your command.
2013-03-26 15:49:55 EST WARNING: terminating connection because of crash
of another server process
2013-03-26 15:49:55 EST DETAIL: The postmaster has commanded this server
process to roll back the current transaction and exit, because another
server process exited abnormally and possibly corrupted shared memory.
2013-03-26 15:49:55 EST HINT: In a moment you should be able to reconnect
to the database and repeat your command.
2013-03-26 15:49:55 EST WARNING: terminating connection because of crash
of another server process
2013-03-26 15:49:55 EST DETAIL: The postmaster has commanded this server
process to roll back the current transaction and exit, because another
server process exited abnormally and possibly corrupted shared memory.
2013-03-26 15:49:55 EST HINT: In a moment you should be able to reconnect
to the database and repeat your command.
2013-03-26 15:49:55 EST WARNING: terminating connection because of crash
of another server process
2013-03-26 15:49:55 EST DETAIL: The postmaster has commanded this server
process to roll back the current transaction and exit, because another
server process exited abnormally and possibly corrupted shared memory.
2013-03-26 15:49:55 EST HINT: In a moment you should be able to reconnect
to the database and repeat your command.
2013-03-26 15:49:55 EST LOG: all server processes terminated;
reinitializing
2013-03-26 15:50:05 EST FATAL: pre-existing shared memory block is still
in use
2013-03-26 15:50:05 EST HINT: Check if there are any old server processes
still running, and terminate them.

I suspect the entry 'server process (PID 3536) was terminated by exception
0xC0000005' is the culpret. Does anyone have any suggestion on the meaning
and cause?
This may be a PostGIS issue but I figured if I'd see if the general
Postgres community would have more of an insight first.

I'm running PostgreSQL 9.1 with PostGIS 2.0 installed on an WinXP SP3: 4GB
RAM machine. Shared_buffers set at 50MB. Let me know if further info
needed.

Cheers

Adrian

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