The strangest thing just happened, I instaled MSN6 on my school computer (Win2k server) and MSN5 and Plus were already installed. I shutdown MSN5 before I installed MSN6 and the installation went fine. I was amazed to find out that the MSN banner was gone, and that MSN Plus! just worked. I think the reason for it not to work while at home, is that I didn't shutdown MSN5 when installing MSN6. I think that's the reason Plus fux0red up.
Hope this helps anyone.