Bind not recognising multiple CPU's

[matt]

Hi all,
I've decided to move one of my named servers to a more powerful and
resilient server.

I've also moved from 9.2 to 9.3 in the server move, which is fine as config
style the seem pretty much identical.

The new machine I'm moving to is a dual CPU machine.

When I start bind I see in the syslog 

Dec 20 11:57:15 alesi named[18438]: starting BIND 9.3.0 -t /chroot/named -u
named
Dec 20 11:57:15 alesi named[18438]: found 1 CPU, using 1 worker thread


I thought I'd try to force the issue with 

Dec 20 11:57:36 alesi named[18458]: starting BIND 9.3.0 -n 2 -t
/chroot/named -u named
Dec 20 11:57:36 alesi named[18458]: found 1 CPU, using 2 worker threads


Which it starts the 2 workers, but it still also only see the one cpu.

Questions.
1.)	How do I make the machine recognize the dual cpu, and split the
functionality over the paid of them ?
2.)	I've dug around and found no problems with running bind over
multiple CPU's but from experience has anyone had any problems with this ?

Thanks 

Matt