gdgt

Netflix is probably required to use the HDCP "features" of that HDMI connection with certain content. HDCP is specifically designed to defeat copying the digital video and audio stream being carried over the HDMI connection. HDMI/HDCP requires a device, like your television, to NOT output DRMed content in a format that might allow one to make a digital recording. Thus, the TV sees that HDCP in enabled, and automatically disables all non-HDCP compliant outputs.

You might be able to output the Netflix video and audio from the PS3 using something other than HDMI. For example, many older AV devices support component video (which uses three RCA connectors for video) that is paired with TOSLINK or digital coax outs. However, I don't know what this might do to the Netflix experience on your PS3. On blu-ray players with such outputs, video will be limited to 720p/1080i; and certain surround sound types would not be supported. And, of course, certain blu-rays wouldn't play at all without HDMI/HDCP.

The most elegant solution to your situation requires an AV receiver that supports at least one HDMI in and one HDMI out. PS3 -> receiver. HDMI out from receiver to HDTV. You would connect the speakers directly to the receiver (assuming the speakers work with a standard speaker connection) OR using an analog passthrough connection (typically RCA) from the AV receiver (not available on all AV receivers) to the HTS3251B/F7 (assuming it accepts analog RCA inputs for each sound channel).