Overdrive: returning audio books early

So, I figured out that now, with the new updates, you can return audio books early.

If they're MP3, you can either return them through your account if you haven't downloaded them, or through the OMC if you've already downloaded them.

If they're WMA, you can only return them early if you haven't downloaded them through your account.  If you've already downloaded them, then you're out of luck, unfortunately.