I tried making films of 576 * 384 (3:2), 480 * 384 (5:4), 480 * 360 (4:3)... and almost most of the films are not playable on iPod and make iPod reboot. They are all playable in iTunes tho.

I am using PC to do the above. However, the discussion here is by far the most professional one, and I think this is probably where I can get a useful answer.

The most DVD to iPod converters for PC restrict the output resolution to 320 x 240, including Xilisoft, ImTOO, and many others. With Cucusoft, we can change the output resolution in the settings to whatsoever you like, but the file produced is always 320x240 if you set output file type to iPod (or mp4).

The only program I have found so far that can really produce mp4 with different resolution is Total Video Converter. I did the conversion and calculate the output resolution in respect to their original ratio and the above rules. They play wells in iTune and the quality of 576x384 looks much better than 320x240 (on my computer, and supposedly on TV). However, they will crash on iPod! Only 2 clips of 576x384 play successfully on iPod and the others, more than 15 of them, don't, not even those with lower resolution, down to 352 x 288 (CIF format).

Do anyone know the reason? Is there any other restriction we need to respect? Or, is there any good program for PC platform that can do the job like handbrake?

The relevant settings I used:
Video bitrate: 1000k ~ 1150k
fps: 29.97 or 30