I believe its a Bando 4pk1680 belt. Gates supposedly sells the same belt part but I've been unable to locate the Gates belt. I believe Your issue is most definitely a stretched belt. Replace it with a new Bando belt and you should be good. If you need I can send you my spare Bando belt to try out. So far I've had no issues with my bando belt.Speaking of the squeak noise people here have described, I actually heard it when I tried to add a little bit more spacer (using 2 small washers) in between the two aluminum pieces. I took them out as soon as I started to hear what sounded like bird noises, then the noise went away. But the auto tensioner noise tapping on the stopping plate is an entirely different noise.
Let me know what the Bando part number is for the belt you currently have.