I have the same problem having had the full game. When I migrated the licenses a few weeks ago, it downloaded a separate copy of the game. Last night when doing some housekeeping on the HDD, I decided to delete both versions since I didn't know which one had the fresh license, and redownload it. No such luck.
In my download history it shows up (although there are a lot of unknown items now), but when I try to retrieve it from there it stalls when trying to initiate the download and eventually gives up. There is no verbose statement that it is unavailable though. And when browsing the arcade games on the Marketplace, most all of them are still there, even the ones legendary for their rubbishness.
The publisher iWin is still around, so I don't think there's a problem with distribution rights. My guess is that it was lost in the move. But I'm going to try doing some investigation on what happened.
Whoohoo! New Wheel Achievements!
