asterisk users - May 2006 - Forwarded Calls crash the system on 64 bit

I have a strange problem. I have a central server with my PRI on it.
There are three peripheral servers connected via IAX. 

I have a 64bit system for my central server and the backup system is a
32bit system. If I have forwarding (sip redirect) turned on and
forwarding to an outside number (i.e. my cell phone) when the 64bit
system is in the middle it will crash. The Asterisk process doesn't
actually crash so there is no backtrace. It uses about 99% of the CPU
and all IAX channels go down and IAX will no longer accept connections.
SIP calls continue as if nothing had happened although audio quality is
compromised due to the CPU being used heavily. A quick "restart now"
fixes it right up. If I bring the 32 bit system up and have it doing the
routing then there will be one-way audio on the forwarded call
(termination point can here the originator but the called cannot be
heard). It does not crash and all the other calls are unaffected. 

Both systems are CentOS 4.2 fully updated and running Asterisk 1.2.7.
The peripheral system is Fedora Core 3 running Asterisk 1.2.7 also. 

-Jonathan