Sometimes when patches are released, they implement auto-switching of where the voice output goes, sometimes this will conflict with our headset, because it will detect the microphone is plugged into the controller, and automatically send voice data to the controller. It does this because it believes the player is using a headset plugged into the controller, and automatically stops sending voice data to the optical port, and ultimately to our headset. The solution for this, is to configure your Xbox360, by pressing the "Xbox Globe" button while a game is playing, and changing your personal settings, so that it sends voice data to "Speakers Only".
The only downside to this, is if for some reason you want to use your xbox communicator in the future, you will have to manually adjust the settings back to "both", or "controller"