Herminator,
Put the spur gear on the other side of the adapter. This not only allow better contact with regular pinion gears, it also allows you to see the gear mesh a lot better. I had a little bit of spur problem in the beginning as well, but once I did this little mod. I haven't strip a spur gear since
I also mentioned it in the supplement sheet that you got with the kit.
Also, I posted a lot of articles in the building tips page of the
www.alexracingusa.com website. Check them out when you guys get a chance
Steve Wang