Quote from Old Timer :I just recently bought S2, I' m not sure if I got Patch Z with it or wether I need it? Load up LFS, and on the main menu, if you have Patch Z, it will say at the bottom 'LFS 0.5 Z' And yes, you'll need Z if you want to play online (and its the best anyway :P)
Open LFS and look at the bottom of the main menu. If it says "LFS S2 ALPHA 0.5Z ..." then you won't need to download patch Z
Open up the multiplayer hosts list, and if you don't have the latest version, it'll prompt you to download it If you have the latest version, it'll just show the list of servers