My images are gone too.
There has been another similar message in "getting started":
BTPS:"#2 - Not one of my thumbnails show up - so I have no idea what the item really is. All the images next to the title say Image not available."
Auctiva Jeff:"I'm not sure why #2 is happening for you, file a support case on that."
If it is happening to alot of us, maybe it isn't just a solitary out-of-the-blue problem?