I just got the ONKYO HTS760 package with the HT-R510 receiver. I hooked up my dvd player to it using digital optical cord. I cant get sound out the front two speakers and center but not the back. I tried the new Star Wars DVD with Dolby Digital EX 5.1 and still nothing. When I press the surround button I can select on, off or auto DD EX but no logo ever displays on the LCD at the top. Ive used the test speakers and the back speakers work. Any ideas whats wrong?