Sounds like you solved your own problem

 

i would try some 8rib idlers(no lip) and see what happens

 

ok there are some pics, i am still having this problem if you see the one idler pulley under the tb , the betl gets wedged behind it everytime the blet flies off, i dont know for sure it the source of my problem but it is catching the belt and its a pita to get the remainder of the belt off after it rips it in half. and when i pulled the blet off it has one wear spot that has no black on it just bare metal so i dont know wtf to do ?? any help is appreciated.