feed dialog: picture not showing up

Question

My Facebook feed dialog link correctly renders a dialog page, but the image set with the picture parameter does not show up -- just the gray line that indicates no picture.<

Answer 1

Since october 1st 2011 every pagetab needs https too.

https://developers.facebook.com/roadmap/

But my image doesn't show up in the feed dialog, althought it's shown up in the fb debug console... :S