DVD upscaling; motion movement pic quality

Can somebody explain to me why that is: When I upconvert my regular DVDs to 720p, the motion movement pic quality is extremely poor. What I mean is when there is a scene where the camera is moving from left to right, ie a landscape, the motion is not smooth at all; the movement starts, stops, moves little bit, stops, starts, stops and so on. The movement is not smooth at all. All other scenes are quite ok until there is a movement across the screen. It gets worse when the movement is quicker.

I had this problem when I hooked up one of the earlier Oppos to my Panasonic AE700 pj couple of years ago and now I'm experiencing the same with my Samsung DVD-R136 (not the best piece of equipment I guess) with a 46", 2y old Samsung 720p LCD.

I always upscale thru HDMI hooked up directly to the LCD or pj. Audio runs thru my Rotel RSP1098 processor.

Is this a common problem? Are there players, chips, processors I should look for? What should I look for in my next 1080p upscaling DVD player. I got quite a DVD collection.... no bluray discs yet.. thx
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I have the Oppo 983 which upsamples DVD's to 1080 via HDMI: Flawless...I've never noticed any digital artifacts at all. They're coming out with their BDP-83 Blu-ray player pretty soon (allegedly...it's been "coming out" for a while now) - It is supposed to use the same Anchor Bay chipset for DVD.
Upsampling is a nifty thing...but not the real McCoy.

I use an Anthem D2 which does a decent upsampling...but it will never beat true BluRay.
I've heard the same sorts of things regarding the blurring, hesitatingly scanning of a scene or the same thing with quick motion scenes with a few DVD upsampling players.

My understading is the same as BR's here... According to the online press for the DV 83 SD DVD player Oppo put out, that anchor bay chip set is a keeper, eliminating this issue.

The upcoming Oppo BR Player is being released on a limited basis now via some sort of lottery... to those who subscribed previously at the Oppo website requesting info on the new Ray player. Following that, as I recall, another limited release will be ongoing with perhaps some changes given the feedback of the first hundred folks on their players.

Currently some limitations, such as no DVD A playback for now, is also one item of note. Reportedly this will be addressed via a firmware update shortly.... or so the news letter I got said, more or less.

So it is coming now... just not quickly or completely it would seem.