backend died

Our customer running Postgres v. 7.3.2 reported a problem, occurring
couple times a week on three different servers, all on Solaris 9.
We enabled debugging in postgresql.conf, now it happened again;
here's the excerpt from the database log:

2004-11-13 10:01:06 [10456] DEBUG: child process (pid 19285) was
terminated by signal 10
2004-11-13 10:01:06 [10456] LOG: server process (pid 19285) was terminated
by signal 10
2004-11-13 10:01:06 [10456] LOG: terminating any other active server
processes
2004-11-13 10:01:06 [10456] DEBUG: CleanupProc: sending SIGQUIT to process
10876
2004-11-13 10:01:06 [10456] DEBUG: CleanupProc: sending SIGQUIT to process
10482
2004-11-13 10:01:06 [10456] DEBUG: CleanupProc: sending SIGQUIT to process
10481
2004-11-13 10:01:06 [10456] DEBUG: CleanupProc: sending SIGQUIT to process
10478
2004-11-13 10:01:06 [10456] DEBUG: CleanupProc: sending SIGQUIT to process
10472
2004-11-13 10:01:06 [10876] WARNING: 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.
2004-11-13 10:01:06 [10478] WARNING: 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.
2004-11-13 10:01:06 [10482] WARNING: Message from PostgreSQL backend:
The Postmaster has informed me that some other backend
... ...

There's no other references to process 19285 in the log file.
If it helps the servers are configured to use UDS.
The socket files are placed in different directories (each db's PGDATA)

Would it be helful to change the debug level from DEBUG1 to a higher value?
What else should I look at?

Thank you,
Mike