When you spin the tire you will see that it is not round but likely has a bump or is slightly oval. It should be round and not out of shape. Viewed from the side as it rotates it will be noticeable. Do try to spin the tire and view it from the rear too. You may see a bulge on the side of the tire if it is defective.
Give the entire tire a good inspection on both sides where the tire seats to the rim. It should be seated properly but you never know.
Did you check the tire pressure as I suggested??

Tire pressure is good and the wheels look good...i took the bike into the shop today to see if they could diagnose the problem....turns out that the rear sprocket drum is loose.... with the bike sitting still i could move the sprocket a good half inch back and forth....probly due to the extra stress on the sprocket from the brake being to tight...mechanic is going to fix it at no cost =)

:tup::tup::tup: