Win32 Backend Cash - pre-existing shared memory block is still in use

I'm getting infrequent backend crashes on a windows instance of PostgreSQL. The error I get is in the log below. It seems to relate to the share memory each time. Does anyone have any ideas what the problem is here, or what additional things I can do to get more information out next time the backend crashes?

I'm running PostgreSQL 8.4.4 on Windows server 2003 Standard.

Much Appreciated,
Jeremy

Postgresql.log:

2010-08-17 16:57:22 NZSTLOG: unexpected EOF on client connection
TopMemoryContext: 268428304 total in 26 blocks; 5528 free (22 chunks); 268422776 used
Local Buffer Lookup Table: 2088960 total in 8 blocks; 501416 free (22 chunks); 1587544 used
PostGIS PROJ4 Backend projPJ MemoryContext Hash: 8192 total in 1 blocks; 5384 free (0 chunks); 2808 used
PL/PgSQL function context: 57344 total in 3 blocks; 22264 free (16 chunks); 35080 used
PL/PgSQL function context: 57344 total in 3 blocks; 28696 free (27 chunks); 28648 used
PLpgSQL function cache: 24328 total in 2 blocks; 5904 free (0 chunks); 18424 used
CFuncHash: 8192 total in 1 blocks; 4936 free (0 chunks); 3256 used
Type information cache: 8192 total in 1 blocks; 1800 free (0 chunks); 6392 used
Operator lookup cache: 24576 total in 2 blocks; 14072 free (6 chunks); 10504 used
Operator class cache: 8192 total in 1 blocks; 3848 free (0 chunks); 4344 used
TopTransactionContext: 24576 total in 2 blocks; 9768 free (8 chunks); 14808 used
ExecutorState: 253952 total in 5 blocks; 83656 free (9 chunks); 170296 used
Combo CIDs: 8192 total in 1 blocks; 4936 free (0 chunks); 3256 used
MessageContext: 253952 total in 5 blocks; 125592 free (1175 chunks); 128360 used
smgr relation table: 24576 total in 2 blocks; 15072 free (4 chunks); 9504 used
TransactionAbortContext: 32768 total in 1 blocks; 32752 free (0 chunks); 16 used
Portal hash: 8192 total in 1 blocks; 3912 free (0 chunks); 4280 used
PortalMemory: 8192 total in 1 blocks; 8040 free (0 chunks); 152 used
PortalHeapMemory: 1024 total in 1 blocks; 936 free (0 chunks); 88 used
ExecutorState: 2097192 total in 9 blocks; 1996680 free (1470 chunks); 100512 used
2010-08-17 19:19:32 NZSTLOG: server process (PID 6684) exited with exit code 128
2010-08-17 19:19:32 NZSTLOG: terminating any other active server processes
2010-08-17 19:19:32 NZSTWARNING: terminating connection because of crash of another server process
2010-08-17 19:19:32 NZSTDETAIL: 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.
2010-08-17 19:19:32 NZSTHINT: In a moment you should be able to reconnect to the database and repeat your command.
2010-08-17 19:19:32 NZSTWARNING: terminating connection because of crash of another server process
2010-08-17 19:19:32 NZSTDETAIL: 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.
2010-08-17 19:19:32 NZSTHINT: In a moment you should be able to reconnect to the database and repeat your command.
2010-08-17 19:19:32 NZSTWARNING: terminating connection because of crash of another server process
2010-08-17 19:19:32 NZSTDETAIL: 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.
2010-08-17 19:19:32 NZSTHINT: In a moment you should be able to reconnect to the database and repeat your command.
2010-08-17 19:19:32 NZSTWARNING: terminating connection because of crash of another server process
2010-08-17 19:19:32 NZSTDETAIL: 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.
2010-08-17 19:19:32 NZSTHINT: In a moment you should be able to reconnect to the database and repeat your command.
2010-08-17 19:19:32 NZSTWARNING: terminating connection because of crash of another server process
2010-08-17 19:19:32 NZSTDETAIL: 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.
2010-08-17 19:19:32 NZSTHINT: In a moment you should be able to reconnect to the database and repeat your command.
2010-08-17 19:19:32 NZSTWARNING: terminating connection because of crash of another server process
2010-08-17 19:19:32 NZSTDETAIL: 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.
2010-08-17 19:19:32 NZSTHINT: In a moment you should be able to reconnect to the database and repeat your command.
2010-08-17 19:19:32 NZSTWARNING: terminating connection because of crash of another server process
2010-08-17 19:19:32 NZSTDETAIL: 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.
2010-08-17 19:19:32 NZSTHINT: In a moment you should be able to reconnect to the database and repeat your command.
2010-08-17 19:19:32 NZSTWARNING: terminating connection because of crash of another server process
2010-08-17 19:19:32 NZSTDETAIL: 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.
2010-08-17 19:19:32 NZSTHINT: In a moment you should be able to reconnect to the database and repeat your command.
2010-08-17 19:19:32 NZSTWARNING: terminating connection because of crash of another server process
2010-08-17 19:19:32 NZSTDETAIL: 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.
2010-08-17 19:19:32 NZSTHINT: In a moment you should be able to reconnect to the database and repeat your command.
2010-08-17 19:19:32 NZSTLOG: all server processes terminated; reinitializing
2010-08-17 19:19:42 NZSTFATAL: pre-existing shared memory block is still in use
2010-08-17 19:19:42 NZSTHINT: Check if there are any old server processes still running, and terminate them.

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