Bind MultiCPU in Debian

[pollex]

Hi, we have installed BIND 9.3.6 and we can't start it with this
feature...
In the other version (bind 9.3.5) we had to add this lines:
/etc/default/bind9
OPTIONS="-u bind -n 8 -t /var/lib/named -c /etc/bind/named.conf"

/etc/init.d/bind9
mount --bind /proc/ /var/lib/named/proc/ -o ro

But now since I compiled the binaries with the command:
STD_CDEFINES="-ISC_SOCKET_FDSETSIZE=4096" ./configure --prefix=/usr/
local/bind9.3.6 --enable-threads

When I start bind I don't even see the line with the processors
found...
starting BIND 9.3.6 -g
03-Dec-2008 10:10:12.716 using up to 4096 sockets
03-Dec-2008 10:10:12.720 loading configuration from '/usr/local/
bind9.3.6/etc/named.conf'

In BIND 9.3.5
starting BIND 9.3.4-P1.1 -g
03-Dec-2008 10:11:10.243 found 2 CPUs, using 2 worker threads
03-Dec-2008 10:11:10.248 loading configuration from '/etc/bind/
named.conf'

Any idea what I am missing here?
Thanks