Selective forwarders not working

Hi,
I have problem in configuring the internal DNS server to perform
specific forwarding. Below describe the internal DNS configuration

In my internal DNS server, I have following being configured :

.....
options {
....
forwarders {
200.200.200.200;
201.201.201.201;
};
forward only;
....
zone "xxxxx.com" {
type forward;
forwarders { 2.2.2.2; };
};


I have no problem with the global forwarders where I use it for
forwarding query to Internet domain names. However , when I recently
try to add selective forwarders to forward any query of xxxxx.com to
be forwarded to 2.2.2.2 instead of the global forwarders
200.200.200.200,201.201.201.201, the selective forwarded fail to work.

Does anyone know where the problem is ? Can I override global
forwarder with a a selective forwarder like the way I defined above ?
I am using Bind 8.3.4.

Thanks & appreciate your help
Tiffany