FreeRadius crash

[Doug Hardie <bc979@lafn.org>]

I am encountering an infrequent problem where FreeRadius crashes  
about once a week on a fairly busy server.  I have a primary and  
secondary authentication server and just a primary accounting  
server.  Both the primary and secondary crash at the same time (well  
the secondary is about 30 seconds behind the primary).  Thus I know  
that it is an authentication request causing the problem.  However,  
using the authentication requests that occurred just prior to the  
crash I am unable to replicate the problem.  I have core dumps and  
have tried to find useful information on the cause but have not found  
anything.  The trace always shows:

(gdb) where
#0  0x280a94ab in pthread_testcancel () from /usr/lib/libpthread.so.2
#1  0x280a1e3c in pthread_mutexattr_init () from /usr/lib/ 
libpthread.so.2
#2  0x2808b450 in ?? ()

FreeRadius 1.1.2 on FreeBSD 6.1 using libpthread.  I have tried using  
libthr but that crashed instantly on receipt of any request so I  
suspect that was not intended to work.  I am beginning to suspect  
that the problem may lie in libpthread.  Is there anything that can  
be retrieved from the core files that might help?  There are always  
several threads active at the time of the crash.