Windows Phone Card Management has unmatched scaling

I see very spotty / unresponsive behavior with silverlight card control on Windows Phone 7 (Microsoft.Phone.Controls.Map). It seems that managing the map does not raise many of my gestures. Does anyone else see this? Is there any workaround?

As an experiment, I connected custom gesture listeners to PinchStarted, PinchDelta, and PinchCompleted. My event handlers get fired every time I clamp, but the Silverlight control doesn't select them “most” of the time.

PS. I use the latest SDK / Toolkits.