[asterisk-users] Segmentation fault on Asterisk startup: res_config_mysql.so problem?

[kjcsb]

When Asterisk starts I get a Segmentation fault
/usr/sbin/safe_asterisk: line 40: 30548 Segmentation fault      (core 
dumped) asterisk ${CLIARGS} ${ASTARGS} >&/dev/${TTY} </dev/${TTY}
Asterisk ended with exit status 139
Asterisk exited on signal 11.

If I remove /usr/lib/asterisk/modules/res_config_mysql.so Asterisk starts 
normally.

tail /var/log/asterisk/full.log
Sep 24 15:46:05 VERBOSE[30608] logger.c:   == Parsing 
'/etc/asterisk/res_mysql.conf': Sep 24 15:46:05 VERBOSE[30608] logger.c: 
== Parsing '/etc/asterisk/res_mysql.conf': Found
Sep 24 15:46:05 WARNING[30608] res_config_mysql.c: MySQL RealTime: No 
database socket found, using '/tmp/mysql.sock' as default.
Sep 24 15:46:05 DEBUG[30608] res_config_mysql.c: MySQL RealTime Host: 
127.0.0.1
Sep 24 15:46:05 DEBUG[30608] res_config_mysql.c: MySQL RealTime Port: 3306
Sep 24 15:46:05 DEBUG[30608] res_config_mysql.c: MySQL RealTime User: root
Sep 24 15:46:05 DEBUG[30608] res_config_mysql.c: MySQL RealTime Password: 
password

vi /etc/asterisk/res_mysql.conf
[general]
dbhost = 127.0.0.1
dbname = asterisk
dbuser = root
dbpass = password
dbport = 3306
;dbsock = /var/lib/mysql/mysql.sock

If I uncomment the dbsock line I get the same result (although the database 
socket warning is not displayed in the log file).

I am using MySQL for CDR logging so I don't think it's a MySQL problem.

Asterisk 1.2.12.1
Asterisk addon 1.2.4

When I install Asterisk I receive a warning:
Your Asterisk modules directory, located at /usr/lib/asterisk/modules 
contains modules that were not installed by this version of Asterisk.

However I cleared out the /usr/lib/asterisk/modules directory before make 
clean && make && make install for both add-ons and asterisk so I'm a bit 
mystified by that.

Could anyone suggest further checks I could do?

Thanks

Cameron