Timing Belt Keeps Coming Off!!!!

[Yup]

I recently replaced my timing belt and now when I fire the aveo up the belt starts walking off of the cams, crank and waterpump. Am I off a tooth maybe? I lined it up perfectly with the old belt and even marked the old belt to make sure everything was exact. Any input would be much appreciated. Need to get this thing on the road tonight.


2004 Chevrolet Aveo Sedan

[xintersecty]

Do you have the big accessory pulley on the bottom? If not it will just walk off. See http://www.aveoforum.com/forum/f81/kinda-lucky-19642/