I have a third-party Mac-compatible external keyboard, the USB 2.0 Keyboard by Matias. On Mac OS X 10.8 Mountain Lion, the keys are all mapped perfectly correctly when I use Sibelius 6 or PhotoScore. However, when I use the same keyboard with Sibelius 7, several of the hardware keys on the keypad no longer perform the assigned function. For instance, I have no way to use the keyboard to add a dot to the length of a note, and I have no way to use the keyboard to put a tie between two notes.
Because this behavior is radically different between Sibelius 6 and Sibelius 7, this means that with the new cross-platform-compiling code base of Sibelius 7, they broke something in the way that hardware keyboard keys are handled and mapped.