I know how to get it to work again ^^. (finally! i missed the function
)
Close your msn and go to properties of the messenger exe -> compability
-> enable the 'run this program in......' and click for vista.
apply this all.. and messenger is back to the place where it used to be in vista = system tray
The windows 7 functions will still work (for me they do ^^) but messenger is back in the system tray....
and you can lock messenger again as in windows vista ^^.
(just found this out for myself a few minutes ago.. so i'm not sure if any features will be gone).
Enjoy!