The new feature is just that...new. It's not perfected and Boris has already stated that some vanilla texture will 'require' fixes or replacements to work correctly. He's implemented it by using height maps in the alpha channels and some vanilla files already have this but are buggy. Same goes for any texture that has a black or white alpha channel.
If he is petitioned, it should be for W7. Even I have left W8 and returned to W7.