Check this thread and the thread that I referenced in one of the posts.

http://www.poolforum.com/pf2/showthread.php?t=6641

If you can reach into the impeller from the basket and move it then the shaft isn't seized. Before you reach in just make REALLY sure it can't kick on accidentally. If it turns easily then the problem is electrical. Get back to us and we'll chase it further.
Al