No rear speaker sounds

[uncle al]

Mr Sky Man came today (see my earlier post) and Sky HD installed OK, BUT, my new Sony Home Theatre system won't play Sky input in full surround, only stereo
My phono leads go from TV out to Sony in as line input.
Mr Sky said I needed to change the Sony settings to Dolby Digital to get surround.
The HTS works fine on DVDs and the old Sky box was fine for surround on all channels (if surround broadcast)
The Sony instructions don't help me really (maybe I'm thick)
Any quick fix suggestions (Mr Sky recommended optical leads but I think I may be able to use phono if I can get the Sony sound settings correct)

[LCDMAN]

Using the two phonos (analog l & r) will only get you Dolby Pro-logic surround sound, so check the Sky HD box is configured to give that.

If you were to use the optical connection out of the Sky HD box to your sound sound amp, then you can access the other surround sound formats that a digital connection allows (DTS, Dolby Digital etc.) provided your amp supports them.