Yep, FM radio should work fine with it. The Denon should be set to bitstream (selecting PCM will cause Dolby Digital 5.1 to be downmixed to stereo and will render DTS soundtracks mute), but that would still get you a PCM source when listening to CD's. I also assume (just covering all the bases) that you have both the center and side surrounds in place and enabled - without surrounds active, 5 Stereo wouldn't be available, and I don't know what turning the center off would do. If you've already covered all of those bases and still don't have 5 Stereo as an option in the "Surr Mode" setting of the "Tuner Input" menu, I'm officially stumped.