Originally Posted by
HSean
.....the tire has nothing in it.....
I would bet the tire does have something in it but you haven't found it. A small wire or tiny piece of glass can work it's way under the tread and be completely out of sight. Give the tire a VERY careful examination inside and out.
BTW, a good technique is to always mount the tire with the maker's logo directly above the valve stem. That way when you get a flat, find the hole in the tube and match it up with the tire. It gives you a better idea of where the cause of the flat occured and saves a lot of random searching.