The reason you're hearing hiss w/ the analog and not the digital is because in some version of the 950 (maybe the blue dot?) outlaw introduced muting circuits on the digital signals. So, if a digital input is not receiving a signal (the CD player is off or on pause), the muting circuits click in and you get silence.

The "hiss" you speak of is completely normal and you won't ever get rid of it. Nor should you expect to. *MAYBE* if you upgrade to a top-top quality pre-pro (maybe top-end meridian or something similar) you might get a little less hiss, but it's there in every piece of gear. My brother-in-law owns a Lexicon MC12B, uses balanced cables from mc-12 -> amplifiers and a PS Audio PP1000 to supply "super-charged" rejiggered power to both amp and preamp, and if we turn up his volume to the max setting, there's some audible hiss at the listening position.

So, don't worry about it.

There are a few things you can do to lower your noise floor though. One is to make sure that all your power cords are seperated and not touching any analog ICs. Another is to try a balanced power unit. I was surprised, but I recently hooked up a BPT Ultra 1 balanced power unit into my system (balanced power units use a transformer to condition incoming power from the wall and then sends 60v down the hot lead and 60v down the neutral lead, instead of the normal 120v down the hot lead and 0v down the neutral, you can read about it various places). I now feed all my equip. except my amps off the BPT unit, and I noticed a pretty good reduction of the noise level.