So I got windows 7

[Shock120]

This issue happens on Vista, Server 2008 and 7.

Funny thing is that this started after a Live update, yet another in a long line of Live updates that fails to deliver anything but fail itself.

As stated, start your own game for a few minutes then check the list, it usually populates by then.

[supersniper]

that's a glitch with halo 2 itself
just wait a couple of minutes or seconds

Also check this sthread for more issues.
http://forums.gamesforwindows.com/t/8021.aspx