do i need a routable ip to join games? i get the error message 'no reply from master server' when waiting for the list of games.

It's possible it may be a firewall issue that preventing you seeing. I would check that out 1st.

i use another firewall besides the Windows' default, and both of them allow the game to connect.
It's not a firewall issue as the game can connect to the master server, but it cannot retrieve the list of games.I could also create an internet game but i didn't stay long enough for someone to join...i've just checked to see if it's possible.