The sound problem lies within the combination Ps3 and BS3.
If you want the use the digital output (optical out) from the ps3, then you need a converter to digital coax.
If you have set the sound option in the ps3 to optical out, then all the produced music formats (stereo, dts, dd etc) goes through the optical.
But the bs2 handles only DD or DTS via the digital coax input! It won't respond to any other format, like stereo PCM 2ch.
So it's either using the analog output from the ps3 to the scart of the bs2, or using the optical ouput from the ps3 to the coax input from the bs2 and only having sound with games or movies.