how to get 720 x 480 video to a nvidia 640x480?

Capture uncompressed using
Microsoft DV (NTSC)
D1/DV NTSC 0.9
Frame rate is 29.97 fps
Frame size is 720 x 480
Depth is 24 bits.
Compressor: 'dvsd'
but in Window's media player the size says 640x480 even though this is
actually 720 x 480.


If I render to
nvidia
Frame rate is 29.97 fps
Frame size is 720 x 480
Depth is 24 bits.
Compressor: 'IV50', Indeo® video 5.11

I suspect that the image will look fine when I later render it to DVD,
But is slightly wide and fat.

I notice that when render to nvidia use 640x480 the image looks is
perfect when playing it back with Windows Media player. but elongated
in premier's playback window.

To summarise,
Nvidia-IV50 and Windows-dvso display different aspect ratios even when
both are set at 720 x 480. using Windows media player.

Any way to fix this?

Thanks,
crzzy1