ignition switch?

So a couple of days ago my starter died, when i turned the key there was nothing (not even a click). Jumping it didnt work so I had my friend hit the starter while i turned they key and voila, it barely started. I had it figured on brushes but got a whole new starter anyways. i installed it and now I'm having a different problem, when i turn the key it just clicks and the starter doesnt turn. This problem is intermittent, happening ~every 7 times. I took it back to the guy who i got it from and he started the motor fine (several times) using a jumper cable connected directly to the battery. He then continued to tell me that it was most likely my ignition switch that had gone bad.

Any ideas?
Thanks.