loss of enterprise admin rights in 2k

Hi. Does any one know of or have heard about a flaw or a trojan that can “grey out” all admin rights in a root DC?
If I go to my GPO’s I find the box greyed out and a statement to the effect that a higher policy may be at work.
If I go to all my admin rights they have lost full control. If I try to re-institute the rights it does no good.
you can mail me a response,tx in advance.