Don,
I had to scroll thru all the forum traffic so fast, I'm not sure if
this will help, but here's my method: Most of my 2D work is done on a MAC
networked with my 3DS machines, including one with a PAR. To compensate for
the difference in pixel aspect, I do Photoshop work with an image size of 752 x
564, which will maintain the 3:4 aspect when you scale the vertical down to 480
and display on the PAR. (I either save a scaled targa from P'shop, or batch
save a bunch thru DeBabelizer, if I've got a lot to convert). I haven't had
any trouble with artifacts being introduced– although since I'm designing for
video, I avoid fine detail, 'halftone'-type patterns, etc. Two minor
advantages: the 752 doesn't need to be re-scaled, so progs like DeBab will do
the job faster, and 752 x 564 fits really nicely on an 800 x 600 monitor!s