Check server ip in Beo6 wireless menu. It must the ip of your BS5 not airport/router.
If the configuration of your Beo6 was made with an older CT (4.11?) delete Beosound 5 and replace it with the version in CT 5.12.
I have no TC but My Beo6 World fine 2way with my airport extreme. So, if your BS5 does work 1way in your system the TC should be not the problem...
Hope this helps
Stefan