How to use ActionSheet while using a MasterDetailPage?

I have a MasterDetailPage, my details page being a list view that uses a custom view cell.

When I select an item in the detail list view, I attempt to display an ActionSheet.
I have tried using all three pages (this.Detail, this.Master and just this).

Each time I get an error on Android saying this: "Android.Views.WindowManagerBadTokenException", with an inner exception of "Unable to add window -- token android.os.BinderProxy@424ec918 is not valid; is your activity running…".

Which "Page" should I be using to kick off an ActionSheet while using a MasterDetailPage?

Regards
Johan