someone correct me if i am wrong..the holes are the same thing...one just holds the set screw for the deflection and the other if for the belt removal tool..but is does not matter what you use for either one...
i had a similar issue with my 900 grabbing the clutch...refer to thread "clutching binding real bad" i think it was called...anyways...it would do what your describing but it would happen on the trail..flat...so long story short...i had the red/pink spring in it, but i think it was sacked out...so this year i used a new black/white spring and its been perfect...every once in a while if i am facing up hill and get stuck..i will creep it slowly back but only once or twice do i remember the secondary binding the belt...but it was never as bad as it was before...i used to have to spread the sheaves to get the belt un stuck..
but i am willing to bet everyones 900 will bind if there is alot of powder, or if its stuck...try sticking a heavier sec. spring in there and try that...