It happened to me today - the correct title + author is shown @ ADE, but it's a completely different book, with the wrong book's cover art. The fellow at my library said he'd heard of it a couple of times before; he thinks it's a publisher error affecting the title in Overdrive system-wide, not just our library. When I asked "What next?", he replied that when Overdrive gets the message he's sending them (next business day), they'll delete the title (so it'll get taken off my own Items Out list), request the publisher send them the correct book, and then send me a (5 day) hold notice when they've added the corrected item.
Since someone's bound to ask:
The book I thought I was getting (and will eventually): The House at Royal Oak by Carol Rizzoli
The one that actually appeared: Where are they bured? How did they die? by Tod Benoit (which my library doesn't own as an Overdrive title, but I read in print and liked!).