pg_reorg -> Anyone has any experience with it?

I was trying to clean up my database and after 2 days of vacuum full on
a 20GB table, I gave up and used pg_reorg which is seriously fast.

However, now I'm not sure if it is the cause of my unstable DB (8.2.13)

I can connect, initiate a simple query and the DB will do down

logs says :
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.
all server processes terminated; reinitializing database system was interrupted at 2009-04-15 15:36:23 MYT
checkpoint record is at 342/CC8E6148 redo record is at 342/CC8E6148; undo record is at 0/0; shutdown TRUE
next transaction ID: 0/460828465; next OID: 158897211 next MultiXactId: 1; next MultiXactOffset: 0
database system was not properly shut down;

automatic recovery in progress redo starts at 342/CC8E6190
FATAL: the database system is starting up

something like

select * from table where condition = 'AX'

doesn't matter which table I do, it will periodically work and then periodically die at the some other time.

I've tried lowering and upping shared memory from 128MB to 200MB(original) to 400MB and it still crashes.

I've no clue how to fix or start to diagnose the issue.

Appreciate any help.