I had my tire rebalanced a couple weeks ago, and we noticed that the inside 3 inches or so were wearing much heavier than the rest. Not dangerous, but evident. Mostly due to the front-end setup on these cars, which provide maximum handling performance, at the cost of increased tire wear.

Your problem sounds a bit different, and I am not sure what is up. Almost sounds like the tire is rubbing on something, but I don't think that is the problem either.