I have an Onkyo TX- DS575 and I cannot get it to go into DTS or Dolby Digital. It will only play Dolby Pro Logic. I have a optical input from my DVD player to my receiever and I am getting sound so I know that it is properly hooked up and assigned in my receiever. I have tried many different DVDs and it will only allow me to choose Dolby Pro Logic. My DVD player shows that it is sending Dolby Digital but nothing on my receiver. HELP!!!