I have been exporting FLV out of CS3 for 2 years now, since I upgraded from ppro 1.0. Its right there in the dropdown at the top of AME where it says Adobe Flash Video. Get it? FLV?
If you are using 720x480 DV source, then you of course know that it is really just 640x480 (NTSC) with a .09 pixel aspect ratio. Flash is square pixels, so when 720x480 becomes square pixels, it is only 640. Plash plays on computers, which are all square pixels unless you have a badly set up monitor.
If you needed to convert your 720x480 DV to 720 square pixels you would need to create a custom project setting not using DV. Try QT, whatever. But round objects will become oval. Which some people think is weird.
Hope that pointing this out was not THAT rude, but whatever.
George Socka
BeachDigital
www.beachdigital.com