Wow. I feel stupid! I've never had consistent luck with the location simulator for my WP apps, and I always just assumed it was buggy. Sometimes I would get PositionChanged events, and other times I wouldn't. It turns out, that there's a perfectly reasonable explanation! If you have your accuracy set to Default, it will ignore the simulator. Of course, at run-time, you want Default for best battery savings (if you don't need high accuracy. The simple answer is to change it based on debugging! I'm glad I chanced to look it up instead of just being frustrated this time.