When connecting with the latest version of iTunes 11 from Mac OS X or windows to Frodo RC3 an error is shown with the following message:
The AirPlay device "XBMC" is not compatible with this version of iTunes.
The old version of iTunes on Mac OS X worked with the same configuration.
The log file doesn't show any abnormalities related to AirPlay.
More people seem to be struggling with this:
No help on github. Use the forum