Problems with Sony TV/DVD setup

Hi there. I have a Sony KV-29F3U Trinitron Dolby Pro-Logic television which has left and right speakers, a center speaker,
two rear speakers and a sub-woofer. I have just got a Sony DVP-NS930V DVD player which is connected with a Scart lead from
AV1 (RGB) on the DVD player to AV1 on the television. When playing CDs and SA-CDs, the sound is fine. However, with DVDs,
there is no right channel.

I've checked all settings and connections, all appears ok. The speakers work fine with television channels and videos and as
I said, it works ok with CDs and SA-CDs, but not with DVDs.

Any ideas?

Cheers,

James.

James Twitchen