Have you ever played a single online battle with another person? (EB, not R:TW)

If not, then you will find that the de facto standard at the moment is for users to connect to a handful of Hamachi networks, using "vanilla" EB. That is to say, an EB 1.2 installation over R:TW 1.5, no sub-modifications. The reason for this is to not allow for an incompatible data error to arise.

Have fun.