Interesting..... I too have tried placing the card into my Montana and, just as WknThDg experienced..... the g2 Lakes chart showed up and appeared to display properly.

Now why in the world did it not work in Homeport of Basecamp ?

This is a mystery. And, unfortunately, beyond my knowledge.

I would think if Garmin has put some other new method of blocking/locking on the card, it would have given me a "Can't Unlock Maps" message at the very least.