never heard of Hamachi.
but, since im a nice guy, il help cdrwolfe.
you need to do the following
A) get the right updates/patches
B) go to
http://www.portforward.com and get the instructions to forward the right ports. You need all the MSN gaming zone ports, as well as MSN Zone Direct X ports (i think)
but then... ive never gotten a game working online - although im open all the time.
-edit-
just checked out Hamachi, and it looks awesome, so im using it now.