Wanted to let everyone know that the Oregon passes the waterproof test with flying colors. I rode the slab for 3 hours on Monday in rain and thunderstorms. I ran the Oregon on batteries to keep the rubber seal on the bottom closed. It was fine the whole time and ever since. This wasn't the first time but definitely the best test yet. I have mine in the RAM cradle.
Sorry, Ozz, can't help with mapsource. Haven't opened it in 6 months.