As Catbrat mentioned, I too am pretty sure it has to do with the HDMI CEC, it is a very handy feature but a bit of a pain for just playing Cd's.
What you could do is use the optical out or coax out from the BR/dvd player opposed to the HDMI and have the cd input linked to the proper digital source, this will bypass the HDMI-CEC and allow the respective compnents to be on and keep the TV off. Yes it is one more cable in the works but not a big deal for one more short cable and the signal quality wouldn't be any different from a cd on either the HDMI or the coax/optical out.
