blk01gti

hey everyone, im new here and would like to say whats up to everyone.
first off i have an 01 vw gti 1.8t. i broke this last week and was wonderin if there were many people in here with vw knowledge. my problem is that my timing belt stripped on the bottom end side. i am not sure if it is a common problem with the cars or if it is something i need to look into a little more?? i have a guy who built the car for me and tunes it but is out of the country for a few months so i figured i would look elsewhere for tips. the top end seemed to be locked up also. i removed the cams and everything seems to look good. i reinstalled them and now everything is turnin free and in good order. is there something that could have caused the belt to slip other than normal wear? it was replaced about 10,000 miles ago. i drive the car pretty hard alot of the time and it has many mods and tuning. maybe that has some affect on it?? well if anyone could help me out it would be greatly appreciated. thanx much, hope to hear somethin soon...