Bug in the MSN (Windows Live Messenger)

I FOUND A BUG IN THE MSN!
The nudge option should happen in each 10 seconds, right? I found a way to display the "nudge" in other users in a period smaller than 10 seconds.
Basically you nudge the person, close the window, open again (do it faster than 10 seconds), and nudge again. You'll see that you will be able to nudge the person several times in a small period.
Application: Version 2008 (Compilation 8.5.1302.1018) - Portuguese (BR)