BUG #2234: terminated by signal 11

The following bug has been logged online:

Bug reference: 2234
Logged by: Kresimir Tonkovic
Email address: kresimir(dot)tonkovic(at)gmail(dot)com
PostgreSQL version: 8.1.0_3
Operating system: Linux debian sarge
Description: terminated by signal 11
Details:

I'm running a script that migrates data from an application that uses
another database to another application that uses postgres. Both
applications are in use during the migration, so it goes in one large
transaction. The job is actually not so big, involves about 60000 rows.
However I'm certain to get disconnected during this job at random stages.
The log says:

LOG: server process (PID 19375) was terminated by signal 11
LOG: terminating any other active server processes
WARNING: terminating connection because of crash of another server process
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.
HINT: In a moment you should be able to reconnect to the database and
repeat your command.

The last 3 messages are repeated for every connected client. After that, it
says:

LOG: all server processes terminated; reinitializing
LOG: database system was interrupted at 2006-02-03 12:42:37 CET
LOG: checkpoint record is at 0/19CF9688
LOG: redo record is at 0/19CF9688; undo record is at 0/0; shutdown FALSE
LOG: next transaction ID: 125842; next OID: 17390
LOG: next MultiXactId: 1; next MultiXactOffset: 0
LOG: database system was not properly shut down; automatic recovery in
progress
LOG: redo starts at 0/19CF96CC
LOG: unexpected pageaddr 0/175A8000 in log file 0, segment 26, offset
5931008
LOG: redo done at 0/1A5A7F7C
LOG: database system is ready
LOG: transaction ID wrap limit is 2147484146, limited by database
"postgres"

I presume this data is not quite sufficient for a good bug hunt, so please
instruct me how to give more data.