Jepp, thats right. RL & RR are empty channels it should be like in the pic in -> Link! Thats exactly my results. Thanks for confirming!
In your post you said that you also had the center channel mapped in mediaportal. But do you hear sound coming from it? I don't.
Sorry, you are right, only FL, FR and RL, no LFE, no Center. My Yamaha is configured for "Pure Audio" (as it is).