Onkyo SR606 5.1 playback on 7.1 system

[statikcat]

Hi everyone. I finally got my 7.1 upgrades and have everything connected. I am using my PS3 as my BD player. Any 7.1 movie (Hellboy) plays back great in 7.1. However, the problem is on a 5.1 track the surround rears are not doing anything! Isn't my receiver supposed to take all rear information in 5.1 and spread it to the extra speakers in a 7.1 config? I looked all over my Onkyo docs and I can't find anything on this.

If the receiver can't do this .. are there others that can? I am upgrading to a Yamaha 3800 in about 2 weeks. Aside from just having dead speakers this messes up my whole setup because if my surround rears are dead in a 5.1 track then my surrounds are coming directly from my sides because 7.1 has a different speaker setup than 5.1.

Ack! If anyone can help I would much appreciate it!