Question about panorama!

It looks to me like your tripod head is at an angle.  That would explain why each consecutive shot is higher than the other.  Next time you should take care to make sure the camera is properly levelled.  Use the horizontal level on the rear screen (press INFO until it appears) or set C.Fn IV-1 to assign it to the M.Fn button to see it in the viewfinder.  Rotate the camera to make sure the level is centred and you should be fine.

--
Ken