BUG #4962: Pre-existing shared memory block is still in use

The following bug has been logged online:

Bug reference: 4962
Logged by: Carlos Alonso
Email address: calonso(at)ictel(dot)com
PostgreSQL version: 8.3.6
Operating system: Windows XP Home Edition Version 2002 Service Pack 3
Description: Pre-existing shared memory block is still in use
Details:

2009-08-01 15:36:08 CEST LOG: server process (PID 5892) was terminated by
exception 0xC0000142
2009-08-01 15:36:08 CEST HINT: See C include file "ntstatus.h" for a
description of the hexadecimal value.
2009-08-01 15:36:08 CEST LOG: terminating any other active server
processes
2009-08-01 15:36:08 CEST WARNING: terminating connection because of crash
of another server process
2009-08-01 15:36:08 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.
2009-08-01 15:36:08 CEST HINT: In a moment you should be able to reconnect
to the database and repeat your command.
2009-08-01 15:36:08 CEST WARNING: terminating connection because of crash
of another server process
2009-08-01 15:36:08 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.
2009-08-01 15:36:08 CEST HINT: In a moment you should be able to reconnect
to the database and repeat your command.
[...]
2009-08-01 15:36:08 CEST WARNING: terminating connection because of crash
of another server process
2009-08-01 15:36:08 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.
2009-08-01 15:36:08 CEST HINT: In a moment you should be able to reconnect
to the database and repeat your command.
2009-08-01 15:36:08 CEST FATAL: the database system is in recovery mode
2009-08-01 15:36:08 CEST FATAL: the database system is in recovery mode
2009-08-01 15:36:08 CEST LOG: all server processes terminated;
reinitializing
2009-08-01 15:36:09 CEST FATAL: pre-existing shared memory block is still
in use
2009-08-01 15:36:09 CEST HINT: Check if there are any old server processes
still running, and terminate them.

There was no old server processes running.
This has happened twice in two weeks, the system was working for five
months.

It is enough rebooting the computer in one case, and starting the postgres
service by windows's services.msc in the other.

Thank's.