I have had this problem earlier but with just some pictures, it does not matter if its .jpg or .png. I did get it to work in my earlier planset ( i dont know how) but now the problem is back again.
I have made a new planset and have placed my logo there. When i import the planset the logo is there but it does not show. It does not matter if i try to import it again or if i take another picture, that does not work either. Its imported but it wont show. Anyone that know whats going on?