SELECT to_timestamp crash PostgreSQL 9.1beta1

Trying to convert unix time to date time format, I encountered a database
crash.

Environment : WINDOWS 7 Professional - Service Pack1

--
-- PostgreSQL 8.4.7, compiled by Visual C++ build 1400, 32-bit
--
SELECT to_timestamp(1306760400);
2011-05-30 15:00:00+02

--
-- PostgreSQL 9.1beta1, compiled by Visual C++ build 1500, 32-bit
--
SELECT to_timestamp(1306760400);
********** Errore **********
--
SELECT version();
********** Errore **********
no connection to the server
--
Trying to re-click on the connection in the pgAdminIII
server closed the connection unexpectedly This probably means the server
terminated abnormally before or while processing the request.

Here are the log files :

FILE : postgresql-2011-06-01_183350.log
2011-06-01 18:33:51 CEST LOG: database system was shut down at 2011-06-01
06:24:09 CEST
2011-06-01 18:33:51 CEST FATAL: the database system is starting up
2011-06-01 18:33:51 CEST LOG: database system is ready to accept
connections
2011-06-01 18:33:51 CEST LOG: autovacuum launcher started
2011-06-01 21:01:01 CEST LOG: server process (PID 3552) was terminated by
exception 0xC0000005
2011-06-01 21:01:01 CEST HINT: See C include file "ntstatus.h" for a
description of the hexadecimal value.
2011-06-01 21:01:01 CEST LOG: terminating any other active server processes
2011-06-01 21:01:01 CEST WARNING: terminating connection because of crash
of another server process
2011-06-01 21:01:01 CEST 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.
2011-06-01 21:01:01 CEST HINT: In a moment you should be able to reconnect
to the database and repeat your command.
2011-06-01 21:01:01 CEST WARNING: terminating connection because of crash
of another server process
2011-06-01 21:01:01 CEST 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.
2011-06-01 21:01:01 CEST HINT: In a moment you should be able to reconnect
to the database and repeat your command.
2011-06-01 21:01:01 CEST LOG: all server processes terminated;
reinitializing
2011-06-01 21:01:11 CEST FATAL: pre-existing shared memory block is still
in use
2011-06-01 21:01:11 CEST HINT: Check if there are any old server processes
still running, and terminate them.

FILE : postgresql-2011-06-01_210902.log
2011-06-01 21:09:02 CEST FATAL: the database system is starting up
2011-06-01 21:09:03 CEST LOG: database system was interrupted; last known
up at 2011-06-01 18:33:51 CEST
2011-06-01 21:09:03 CEST LOG: database system was not properly shut down;
automatic recovery in progress
2011-06-01 21:09:03 CEST LOG: consistent recovery state reached at
0/16E2DA0
2011-06-01 21:09:03 CEST LOG: record with zero length at 0/16E2DA0
2011-06-01 21:09:03 CEST LOG: redo is not required
2011-06-01 21:09:04 CEST FATAL: the database system is starting up
2011-06-01 21:09:04 CEST LOG: database system is ready to accept
connections
2011-06-01 21:09:04 CEST LOG: autovacuum launcher started

Thanks,
paolo saudin