With the new IC2 v1.71, I was eager to try it. Unfortunately, after a few seconds (ranging from 5-30), the game crashes. The world doesn't seem to be damaged when this happens, and the error screen is too fast. Both ModLoader.txt and the console output don't say anything of value.
I am using forge 1.3.3.12 and IDresolver Forge 1.3.3 edition. With IC2 v1.64 it works, unsure about v1.70, because the section in Public Releases was removed.