Audio from my toshiba does not come out of my onkyo s5300

Hello all,
I just recently purchased the onkyo s5300 home theater and I am having some difficulties with it.

-I have my ps3 connected directly to the receiver and it sounds great, I know it takes some tweaking depending on your preference but I get a pretty great surround sound experience.
-Now the problem is when I am watching standard television the audio comes from my tv speakers. I have the tv connected to the audio out on the receiver via HDMI. The receiver is set to tv but no Audio comes out from the speakers. The model tv I am using is the Toshiba 32AV502R. I do not know if I have to change any settings on my television or what.
-I then tried connecting my cable (cablevision) directly to the receiver via the hd optical wires it came with, the sound does come through the onkyo speakers but only the front right and left speakers, and the left speaker sounds awful. Which I do not understand because it works great when watching a movie on my ps3. I really want the surround sound experience when watching tv. What should I do? Please help. Sorry I did not know where to post this

Hey JChin, thanks for the reply. I do not have the cable box connected to my tv via hdmi when I try to do that it says my tv does not support hdmi. Weird because I would connect my ps3 to it via hdmi and it would work just fine. So I guess the latter option is my only option. Could you tell me how do I change the cable box audio? Thanks