Try clearing your cookies.
I did that and it looks like I can vote about every 10 minutes or so. At least the % changes after I submit.
If you open your cookies folder and just delete the one from that site and hit refresh, you can vote as fast as you can delete the cookie, refresh, and click. Not that I would do that, because it would be cheating. :)
When the delegates emerged from the Constitutional Convention in 1787, a Mrs. Powel of Philadelphia asked Benjamin Franklin, “Well, Doctor, what have we got?” Franklin replied, “A republic, madam, if you can keep it.”