Page 1 of Wharfedale 750s - Dolby Digital 5.1 Problem

I am attempting to connect my Wharfie 750s to a Sony HTBE1 home cinema system.

I connected the two using an optical cable. I used Minority Report to test the setup. When I have the DTS soundtrack on, everything is just fine. However, when I switch to DOlby Digital 5.1, the HTBE1 only outputs through the left and right front speakers and the Sub-woofer. I know this through listening, and because the Sony display indicates that only these speakers are active.

WHen on DTS, the led under DTS on the Wharfie is lit, when on Dolby Digital, th eled under that logo is lit. I swapped for other disks, but the same problem occurs.

When I hook my x box up to the sony in the same fashion, there is no problems at all with dvd playback, so I am confident the sony set-up and leads are all OK. The problem is with the wharfedale.

Anybody have any suggestions?

Thanks for the help!