Asterisk Cores when voicemail is accessed

Good afternoon,
I have a 1.8 Asterisk (PBIAF implementation running on ESXi 5.0. This was recetnly V2V’d to this host from an esxi 5.1 host where it ran flawlessly for many months. Now when voicemail is accessed I get the following message on the console;
asterisk[2017] trap invalid opcode ip:49665a sp:7f1190a7e320
error:0 in asterisk[400000+1cf000]
/usr/bin/safe_asterisk: line 145: 1859 illegal instruction (core dumped) n
ice -n $PRIORITY ${ASTSBINDIR}/asterisk -f ${CLIARGS} ${ASTARGS} > /dev/${TTY} 2

&1 < /dev/${TTY}
Asterisk ended with exit status 132
Asterisk exited on signal 4
Automatically restarting Asterisk

That looks bad, version information below. Anyone seen this issue before?

PIAF Installed Version = under VMWARE
FreePBX Version =
Running Asterisk Version =
Asterisk Source Version =
Dahdi Source Version = 2.6.1+2.6.1
Libpri Source Version = 1.4.12
IP Address = 172.31.x.x on eth1 │
Operating System = CentOS release 6.3 (Final) │
Kernel Version = 2.6.32-220.17.1.el6.x86_64 - 64 Bit … +Backtrace

Note, if PBIAF are using modified source code, you will need to submit bug report to them, rather than

No this is out of the box install of PBIAF/Asterisk.