asterisk users - May 2010 - Can't load ooh323 on Centos x86_64: capabilities failure

I have a Centos 5.4 64 bit installation.  I've tried installing asterisk
1.6.2.7 from source, and from RPM, and although overall things work, the
chan_ooh323.so module won't load.  Every attempt to load causes
"Capabilities failure for OOH323. OOH323 Disabled."

I looked at the source and the call to ooh323c_set_capability(&gPrefs,
gCapability, gDTMFMode) fails, but why isn't obvious without tracing through
code that is totally new to me.

Can anyone offer ideas?  I have a 32-bit similar OS installation which runs
fine.  Could this be a 64 bit issue?

MD