MKMapView memory usage is steadily increasing

Question

In my application, I noticed that when you click and display a view controller containing MKMapView , memory usage is steadily increasing. I decided that the problem with MapKit itself, and not with my code. I made a test project containing just a navigation controller, in which I can repeatedly click and set a view controller containing nothing but a map view, without annotations or overlays. When I click and click on the view controller again and again, memory usage increases by about 0.6 MB every push / pop cycle. Any thoughts on why this is happening? I am using ARC. Thanks!

Edit:

I did some testing in the iOS 5.1 simulator (I know about the problems associated with profiling in the simulator, but I don’t have any iOS 5 devices to test), and my results show that this is a bug in iOS 6; in iOS 6, I see a gradual increase in memory usage, but in iOS 5, memory usage doesn't increase. I believe this is a problem with Apple's new proprietary cards.