I have the same problem (on a x64 platform). I couldn’t solve it so far so I’m still surfing for help. In the meantime I installed VLC and it “works”, which means that it is not a problem of codecs (I’m using K-lite pack).
Btw, I said “works” because it doesn’t work too well. Sometimes it doesn’t play some DVDs (and sometimes it does). Or, it freezes. But you, this what you get for free. That is why I always say: if you want something that works you need to compromi$e 🙂 (in Linux e.g. I couldn’t even make the sound work)
hope we can solve it