Those are the D1S (not II) specs; they don't seem to have reprinted the manual for the II (mine came with a D1S manual)... I think the only place I saw the third item that was different was in a review. Long lost/discarded, of course.
Figured I'd bump this as it was what brought me to this site in the first place, and perhaps add a bit of info to this.
The manual for the D1S II was changed, but they forgot to update the wattage. What they did update were the pages on the remote control (the II used the VSX-053 remote, and the D1S used the VSX-014.) The manual for the II clearly shows the 053 remote and functions instead of the older remote.
You are correct though, that power specs changed slightly. This was forgotten to be updated in the manual, but I *had* a 1992/1993 Pioneer product lineup brochure that detailed the D1S II and it's specifications, which showed the slight change in power output. I'm not sure if this was ever available in the states, as I got mine in Hong Kong, though it was in English. Sadly, I lost it in a move just a few months ago.
As far as the years go, the D1S came out in 1990, and was continued with no changes for the 91 model year. In late 92, the II was released, and continued into 93, and in 94 they released the D2S.
I just purchased another D1S after selling my old one many years ago, it still puts out a great sound.
Todd