The 720x480 setting results when you press the NTSC button. I asked several times in this thread for someone to tell me the NTSC DVD Widescreen resolution but never got an answer. The NTSC resolution related to the button appears to be broadcast 4x3 resolution. When you burn that to DVD, many people select DVD Widescreen resolution. The result is that it takes the 4x3 signal and stretches it a bit to make it 16x9. I think it still looks great but some people prefer to render in true 16x9 format. They typically do this by setting the model to 1280x720 and then scaling the result down to whatever the DVD NTSC widescreen resolution is. Obviously, this takes much longer to render.
For a time, I was setting all the models to the NTSC resolution. Those who wanted something different either requested it or changed it themselves. Now, almost every request I get seems to specift 16x9. So, I take that to mean that they want the model to be set at 1280x720. So, now that is my default unless otherwise specified.
I still wish I knew what DVD 16x9 widescreen resolution was. Perhaps it is 720x480 but the aspect ratio is just forced wide somehow or pixels are not square. I don't know.
No problem on the paypal issue. I'll keep my eye out for it.