Maybe one of you should explain why
Stuff Plug basically checked when the window was opened by seeing if the two msns set a connection somehow... but the thing now is whenever someone signs in or just randomly, a connection is made to see the person's DP. Considering you see their DP when they sign in and on your contact list, msn keeps "opening" connections to every contact to tell you what their DP is... so SP would tell you someone opened a window even if they didn't