VACUUM causes violent postmaster death

Server process (pid 13361) exited with status 26 at Fri Nov  3 17:49:44 2000
Terminating any active server processes...
NOTICE:  Message from PostgreSQL backend:       The Postmaster has informed me that some other backend died abnormally
andpossibly corrupted shared memory.       I have rolled back the current transaction and am going to terminate your
databasesystem connection and exit.       Please reconnect to the database system and repeat your query.
 

This happens fairly regularly.  I assume exit code 26 is used to dictate
that a specific error has occured.

The database is a decent size (~3M records) with about 4 indexes.

-Dan
-- 
Man is a rational animal who always loses his temper when he is called
upon to act in accordance with the dictates of reason.               -- Oscar Wilde