postmaster shutdown

This behaviour is starting to get on my nerves...

Could somebody give me a hint as to what exactly happened here and how I
can avoid it in the future?

This is the relevant bit of the Logfile:
----------------snip----------------
2002-03-06 16:02:52 FATAL 1: Database "template0" is not currently
accepting connections
2002-03-06 16:02:53 FATAL 1: Database "template0" is not currently
accepting connections
2002-03-06 16:02:53 FATAL 1: LWLockAcquire: can't wait without a PROC
structure
2002-03-06 16:02:53 DEBUG: server process (pid 1848) exited with exit
code 1
2002-03-06 16:02:53 DEBUG: terminating any other active server
processes
2002-03-06 16:02:53 NOTICE: Message from PostgreSQL backend:
The Postmaster has informed me that some other backend
died abnormally and possibly corrupted shared memory.
I have rolled back the current transaction and am
going to terminate your database system connection and exit.
Please reconnect to the database system and repeat your query.
[this message is repeated six times]
2002-03-06 16:02:56 DEBUG: all server processes terminated;
reinitializing shared memory and semaphores
IpcMemoryCreate: shmget(key=5432001, size=2039808, 03600) failed: Not
enough memory

This error usually means that PostgreSQL's request for a shared
memory segment exceeded available memory or swap space.
To reduce the request size (currently 2039808 bytes), reduce
PostgreSQL's shared_buffers parameter (currently 128) and/or
its max_connections parameter (currently 32).

The PostgreSQL Administrator's Guide contains more information about
shared memory configuration. [that wasn't really too helpful on this
matter; next I started up the service again. The subsequent entires go
along as follows:]

2002-03-06 16:15:25 DEBUG: database system was interrupted at
2002-03-06 15:58:24
2002-03-06 16:15:25 DEBUG: checkpoint record is at 1/E3952A78
2002-03-06 16:15:25 DEBUG: redo record is at 1/E3952A78; undo record is
at 0/0; shutdown FALSE
2002-03-06 16:15:25 DEBUG: next transaction id: 8343789; next oid:
2876559
2002-03-06 16:15:25 DEBUG: database system was not properly shut down;
automatic recovery in progress
2002-03-06 16:15:25 DEBUG: redo starts at 1/E3952AB8
2002-03-06 16:15:25 DEBUG: ReadRecord: record with zero length at
1/E39594F8
2002-03-06 16:15:25 DEBUG: redo done at 1/E39594D0
2002-03-06 16:15:27 DEBUG: database system is ready
----------------snip----------------

I have absolutely no idea what I should do about this. Most of the time
the thing is running fine, but it just quits occasionally. It's
PostgreSQL 7.2 running on Cygwin, Win2k, 2GB RAM, quad-processor by the
way, we are doing access via ODBC. I'd be happy to provide any more
information if it could help in solving the problem - and I'd be very
happy about helpful advice.

Thanks in advance,

Markus