Optical cables do not carry HD Surround.
As far as where the problem is, there is a chance it's before the receiver, but maybe I should have said that since you lose video and not audio points to it being after the receiver.
hdmi handshake can be voodoo. It could be the PS3. Like I said way back, I had a Panasonic BR player that kept dropping hdmi, regardless of how many cables I tried. I have a lot of equipment, and nothing else drops. I do know that when there is an hdmi problem, it can be infuriating trying to find where the problem is. It's frequently not where you think it is.
As far as where the problem is, there is a chance it's before the receiver, but maybe I should have said that since you lose video and not audio points to it being after the receiver.
hdmi handshake can be voodoo. It could be the PS3. Like I said way back, I had a Panasonic BR player that kept dropping hdmi, regardless of how many cables I tried. I have a lot of equipment, and nothing else drops. I do know that when there is an hdmi problem, it can be infuriating trying to find where the problem is. It's frequently not where you think it is.