I have about a 6 year old reciever. It's a 5.1 and does Dolby Digital and DTS. I recently got a PS3 and watched my first blue ray disk last night, for some reason I could't get surround sound at all. The BD disk says the audio is in 5.1DTS HD, so is this a new format that I have to upgrade my reciever to get?

There is no HDMI on my reciever, so It's connected HDMI for video to my tv and digital (toslink) to my reciever.

I have all the settings on my ps3 to automatic or the recommended settings.

Is there something I can do to get surround sound, or do I have to upgrade my receiver?

to get the new audio codecs you need to get a different receiver, or a player which has analog outs (assuming your receiver has these). There shoulld be a way to get the PS3 to output standard dolby or dts to your receiver you now have.