Well, applying MC Patcher after copying ModLoader and Forge into minecraft.jar render IC2 inactive
Using Sphax textures without MC Patcher causes 'miniportal' and 'minifire' on the smoothstone...
I will try Optifine, and if this do not help, I guess I have to learn to love the default textures
Anyway, thanks for your answers gentlemen.
EDIT: Looks like using OptiFine AFTER ModLoader & Forge do the trick! Many kudos ultimate_omega!