>>   I doubt it's anything to do with 64 bit operations - I'm not seeing any
>> great number of unimplemented instruction traps.
>
>  It is not anything to do with the toolchain.

My booboo. I was getting the two problems confused. The toolchain / 
emulated instruction issue is still there, though.

Just curious - what would happen if unimplemented instruction traps 
happened during the handling of the page faults?

Thanks,
John