MasterDetail Page Icon Rendering Weirdly

Hi,

I have set up a MasterDetailPage and when viewing the 'detail' (itself a NavigationPage) the page icon for the master is displayed top left of the navigation bar.

This is fine but the icon is rendered rather strangely though - it appears to be a 1-bit render of the image set in the colour defined by NavigationPage.BarTextColor.

Is there any way to get this image to display correctly?

I'm running on the iOS simulator.

cheers