first, it's Messenger Discovery, not MSN...
Second, the plus! logo and the MDX logo use a diffirent method of hooking (i hope i'm right here
) so they should not conflict, the plus! logo does dissapear in some skins but i don't think that's your problem.
i just don't think they conflict, i guess (tho the odds are small) that plus! isn't working the way it should?