The only time I have see bets returned like this is when you bet over the limit. I don't know what is going on. I would hold off on all bets until SatoshiDICE has a statement.
Its happened more and more the last few months; seems like they have some dynamic adjustment of the max bet going on. Somebody wins and the max bet immediately goed down so your bet that was within the limits suddenly isn't anymore. That being said, if even bets of 0.015 on the 50% aren't processed anymore........
and lol at maximum bets and odds:
