No offence, but I think this is all bullsh*t, I don't like the prequels and I hate the idea of adjusting the OT to match with them. If the prequels were never made or were made with more thought of matching the originals (which is the way it should have been not vice versa) we could think that Vader became evil by choice, out of lust for power, not because he was lame. And we could think that he never knew that this woman he once raped had a son (or, as we sadly later learn, twins). But then, when he chases Luke in the Death Star trench and he feels that "the force is strong with this one," which must have been pretty rare in the dejedied galaxy, and later hears that this boy's name is Skywalker he can surely add two and two together. But I think the theory that he'd known all along and even knew where Luke and Ben were is totally off the track and can only be thought of because of the inconsistencies the f*cking prequels created...