I have just upgraded ADE to 4.1? and now I can't see any book covers, only a grey space. Books seem to have come across but page is certainly lacking colour and movement. I quite like to see the covers and would like this feature back.
Do you mean Version 4.5? This Version are display also the eBooks. If was not right display. Go to the My Digital Edition folder and rename the order to My Digital Edition.old. You should found the Folder in your Documents.