Volvo: Timing belt, mles, timing belt

Question
The timing belt on my 1999 s70 (2.4 non turbo) walks off the gears until it hangs about 1/4 in off the gears just skimming the plastic cover(the belt was replaced about 1500 mles ago). What's going on and how do I correct this?  

Answer
Dan,
Not a common problem. There must be a idler pulley that is wrong or somehow mounted incorrectly. You will have to "eyeball" and see if you can see the trouble. If you can not do that then get the car to someone quick you do not want that belt to come off you will do major damage.