How do I get an English Dolby Digital sound track out of the Star Trek (2009) Blu-Ray disc?

My player (Sony BD-370) is connected to an older Dolby Digital receiver via SP/DIF coax. The available sound tracks appear to be English Dolby TrueHD, French Dolby Digital, and Spanish Dolby Digital. On my receiver, I get surround only in French and Spanish. When selecting English, I only get stereo. Doesn't Blu-Ray require a Dolby Digital primary sound track? If so, and its on there, how do I access it? (Please don't answer with "learn French", that's already been suggested.)