Okay...keep trying. Again, some shows are listed as 5.1 but, for some reason, aren't actually in it. Californication, being a TV show, might show 5.1 for the series, but some episodes might be in stereo.
In the main PS3 menu system, go to Settings/Sound Settings/Audio Output Settings. Select "HDMI" (which I'm sure that you have), then select "Automatic", and then on the next screen double check that "Dolby Digital 5.1 Ch" and "Dolby Digital Plus" are listed. I'm guessing that they are if your blu rays are working, but I wanted to mention it.