This is also what Terry told me, however it doesn't make sense as apparently numerous people have swapped the ring gear without having to swap the output shaft as well.
As well, I do not get the gear stepping problem 100% of the time, only some of the time. Other times everything will spin like butter like it should, sometimes it won't. It's totally hit or miss.

Damn it this is pissing me off. As soon as it stops raining I'll probably take it apart, a FORTH time.

-mobiuslogic