Yes, allegedly Warner have admitted a problem (albeit behind closed doors) that there is a fault with the audio mastering on both Last Samurai and Phantom of the Opera. I've yet to see confirmation of this from anyone of any real authority to confirm it for sure however.

Million Dollar Baby didn't come out on the 18th as planned and was delayed, and confirmed by Warner, due to 'technical issues'... It's purely guesswork whether such issues suggest Warner caught the audio problem in time before sending that title out. Serenity from Universal is apparently just fine. We'll have to see if Million Dollar Baby turns out to be any different when people get their hands on it over the coming week.

The problem certainly doesn't seem to be related to the fact the player is having to do real-time re-encoding of the DD+ track and turning it into DTS when using SPDIF. Some have suggested it might actually be down to the different ways a disc can be authored with regards to the iHD menu system, but as I say, we're now hearing reports claiming it to be an error on the mastering end that the Studio is at least aware of it. We'll have to wait and see how things turn out.