PS3 blu-ray no 5.1

[dtr20]

OK first things first, my PS3 is hooked up to my Insignia 42' plasma hdtv via HDMI. From my TV is an optical cable to my receiver. Before I updated my PS3 firmware to 2.10, blu-ray movies 5.1 audio worked fine. Since then I can either get nothing or 2.0. I have the Blu-ray movie audio output set to bitstream and not Linear PCM. I only have 1 optical port on my receiver, I want to be able to listen to 5.1 sound coming from my PS3, and hd cable channels, this is the only setup I can do without unplugging cables on a regular basis, or buying a new receiver (it works fine for now). Like I said, I just started having problems about 2 weeks ago when sony released the 2.10 firmware for PS3. My whole setup worked fine with the 2.0 and 2.01 firmwares. Does anybody have a clue?