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

An alternative problem I experienced was that I had already shared the image to facebook and at that time had authentication enabled for the site, which I then disabled. However when I tried to share with facebook it had seemed to cache the previous issue and that was causing the problem. Changing the file name or trying again later would resolve it. In my case I deleted the image and made a new one (they were dynamic)