Unless both components have HDMI 1.4, the ARC (Audio Return Channel) will not send the TV audio back through the HDMI. (I don't think the LE32C74BD does.)
You'll likely need to connect your TV to your receiver, either with analog (RCA) cables, or optical audio cables to send the audio from the TV to the receiver, and you may need to select "External Speakers" in your TV's audio menu.
I just picked up my new Samsung HT C5200 blu-ray player and after connecting it up, the speakers work when watching a DVD, but are not working when I'm watching standard TV. The blu-ray player is connected to my Samsung TV (LE32R74BD) via HDMI and I have also wired them with a composite video cable.
Its probably a basic error on my part, but any help would be much appreciate.