It seems that the BD+ copy protection might be too good for its own good.
In a story from DVD Town, it looks like the following Fox Home Entertainment Blu-ray Disc releases are having trouble: The Day After Tomorrow and Fantastic Four: Rise of the Silver Surfer. These discs contain the BD+ layer.
Basically, "BD+ is an extra layer of copy protection. With it, Sony should be able to change the keys used to unlock it. In short, this means that if a BD+ disc is hacked and copied, Sony can change the keys that secure future discs from being copied."
It seems that "some Samsung players may be unable to play the discs, but a firmware upgrade should be available or in works. However, other people say they will not play on the latest firmware from the company. Panasonic players will play the discs but load times are high. Again, Playstation 3 seems to be the safest bet when it come to Blu-ray. It seems to play BD+ without problems."