Discount Tires sold me a set of 4 tires in March 2011. In July I noticed they were wearing on the middle tread only - to date, they have not resolved the problem.
I had it checked at their store and it was NOT from over-inflation. They blame it on the miles I drive each day -- not even a good excuse in my book.
The manager at the Madison Store was very pushy and when I would not look at him, he became almost belligerent. I feel that the tires are defective and that they should replace all four tires.