There are lots of things that can cause issues with that belt it seems. The tolerances around the front water outlet is the worst... the belt slaps against it and starts to wear. The other thing is that I've seen pull ropes fray and drop debris in the housing which then causes an issue.
My '00 800 had like 3500 miles on it over 2 seasons before it failed. Since then I've been leary to go more than a year without checking it and replacing it.
Also, if you ever pull it off and want to reuse it, make sure and note the direction the belt went on. I've had several guys pull their belt off and within a ride or two of reinstalling it fails. I'm guessing it has worn in a certain way and it doesn't get put back on the same direction or maybe even the same teeth and that causes the failure.
sled_guy