Weirdest thing just happened.
Was playing Rainbow 6 on Co-Op (brilliant by the way incase you are insane and havent bought it yet) and I decided to try my wireless headset.
Powered it on, started flashing, pressed the sync button on the headset and then on the console.
Quadrant 1 was lit, I then pulled my, its gonna change to quadrant 2 face, but it didnt, it worked.
To test it again I hit the sync button on the headset and then console again.
Q1 again.
Turned off my xbox, powered on with pad, waited till signed in, then turned on headset again, voila, Q1 yet again.
Cant say I have done anything else except I was using the wired headset just as I powered on the wireless then disconnected as it was detecting the xbox.
Give it a go with a different game.
See if you can get it working.
Might be worth try a private chat as well with wired then try and switch to wireless.
Will post back tomorrow if it does the same thing in the morning.