Priority of Privileges

I'm trying to understand privileges and I think I'm misunderstanding
something. Here's the situation (simplified).

I have different users on the site: guest, reguser, member and admin

now, I want to have some editors, so I create an editor role and assign that
to select members. So the editors belong to two roles: Member and Editor.

to help them, i create a small menu block with editing links: EditMenu

when I create the block it is visible to everybody, so I create a privilege:
DenyEditMenu and assign that to Everybody. Now the menu block is hidden,
this is good.

next I want the Editors to see the block, so I create a privilege:
ViewEditMenu and apply that to the Editor role

but, the block doesn't show up, because the DenyEditMenu is applied to
Members and the ViewEditMenu is applied to Editors and an Editor is a member
of both Editor and Member. And the Deny privilege trumps the View privilege.

Is there anyway to tell Xaraya to allow the Editor privilege to trump the
Member privileges?

TIA
jalal