I contacted Outlaw with my serial #, and Scott told me he'd put me on the list for a replacement, so I guess I didn't have the latest rev. of the 950.
Also, turns out the hiss in my unit does NOT increase or decrease w/ the volume (even above 00db).
Thanks to everybody for your help!
And, for what it's worth, I don't think the current level of "hiss" on my 950 is unacceptable or anything. I definately DON'T think it matches the specs in the manual (which indicate a S/N Ratio of 100dB on the digital inputs), but it's not that bad.
My first DD receiver (granted it was ~$500) had (if memory serves) similar "hiss".