Hey! So you don't worry about it over the weekend, I looked it up again and they are the correct belts for your bike
You are Mr Wright with a 2002 ST2 right?
Enjoy!
No, I'm Mr. Winkelman with a 2001 900 Supersport.
Other than the square tooth-round tooth thing, I can't imagine why the SS would need a different P/N than the M900. It's the exact same friggin mill. Sometimes I really hate factory part numbering schemes...
(I used to work in a parts house, so I've dealt with this before)