Compmgmt. on remote computers

Can anyone explain to me why, when I use "manage" this
computer from within Active Directory/W2003, the msc
screen opens, but there is a red cross in local users and
groups on that computer and I can not connect to the
event.log I'll get a "ACCESS DENIED" message. It's not
with all the client-computers only a few. I do have logon
locally rights and I am a member of the Administrators
group.

Thanx