Security Groups between 2 W2K trees on 1 single frest

From: Trebbia Xavier (xtrebbia@shvgas.com)
Date: 12/05/02 

From: "Trebbia Xavier" <xtrebbia@shvgas.com>
Date: Thu, 5 Dec 2002 05:30:53 -0800

Gentlemen,

I have a single forest with multiple trees and domains
(each remote site has its own tree).
My W2K forest works on Native Mode.

On my root domain, I've created a "Global Security" Group
but I Can't add any other domain security Group.

Is there any way to perform the restriction ?
Is there any know issue or restriction which impact my
settings ?
Thanks for your help.

Xavier