Windows Media Player + Windows Live Messanger?

When i'm playing a song on WMP, it doesn't appear as a song that i am listening to on Windows Live Messenger, on WLM the "Show what i'm listening to" on thing is Checked. I dont know if there is a setting in WMP that will change this, or a setting in WLM if anybody knows please tell me how to make it show what im listening to in WMP!!!