I've found that doing force stop, clearing the cache and data, and possibly uninstall updates then restarting the Market app will fix stuff like this.
From time to time the Market app seems to get confused and with frequent, silent updates it isn't easy to know what the state of the app is. Doing these steps will put it back to stock before having it jump to the newest version. In just about every case I've seen this gets images back and things working again. There's no downside to doing this process that I've seen... all of your paid apps and backups remain once all is working again.