I've got simple exercise about nodal analysis and superposition. I need to use these two methods in order to calculate current i1. My attempt is here: http://i50.tinypic.com/nq3e45.jpg . Unfortunately results from both methods are different. I guess I took current source into account in superposition method improperly. Can anybody tell me, please, what is wrong with my solution? (The second required thing is to calculate powers in this circuit).

Thanks for help in advance!

Greetings!