I have the same lip sync problems as does everyone else on here regarding playing Blu-ray discs. Your marketing campaign was a debacle for sure, and surely your PR staff's worst career-so-far nightmare.
So, please just fix this most-basic issue. Your new firmware update, as you know, did not target this issue. And the fact that the blu-ray's drive functionality as a movie player is dependent, entirely, on a software app. is low blow, even for some like me who understands the DRM issues that are of importance to developers, distributors and the all-important bottom line.
Like others have said, disabling 24Hz helps. However, that defeats the purpose of MS even listing 24Hz as an option.
This issue is not something a consumer should be beta-testing for you, especially at this stage.