I just wanted to point out my experience with my RM-V302
I quickly programmed everything, except my Hughes DSS receiver. It seemed as though no code worked on the DSS button. (even cycling through the codes)
I eventually read in the manual about how the DSS / DVD / RCVR buttons could be assigned to other components. I then changed the DSS button to (gasp) DSS, then in code discovery, I was able to finally control my DirectTv receiver! Moral of the story, do not assume the 3 selection buttons will automatically control what the button stands for.