First, the easy one. The DTS bug is old news -- your 950 came with the latest software, which means you are already bug-free. 950's shipped prior to mid-March 2003 have an issue with LFE on DTS-ES tracks that requires a chip swap-out to correct.

As for 5 Stereo and 7 Stereo, it's been a while since I used them. I do recall that they steer more sound to surrounds than other true "surround" modes -- the goal of the 5/7 Stereo modes is just to duplicate the stereo signal all the way around the room. When we used 7 Stereo with some TV material one evening, I happened to walk behind the couch (closer to the rear soundstage) and when facing the left or right surround (both of which are dipoles, not direct radiating) I had a very weird sensation of confusion due to the full audio content being distributed through the surrounds at the same time I was turned 90 degrees from the intended direction. You may be experiencing much the same thing, with the surrounds doing more than you expect. This is why a number of 950 owners have referred to 5/7 stereo as "party mode" -- all-encompassing background music for a party, without the finesse of PLII or Neo:6.

------------------
gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review