I have spent a while trying how to convert a PALDVD to NTSC DVD. I purchased a DVD boxset from Australia because they will not release this DVD set in the states. The DVDs were region 4 and in PAL- incompatible on USA DVD players. I played around for almost 2 years and have figured how to make it work!
I used the following to make this work:
-DVD Fab (Latest version)
-Powerdirector (Full version 8)
Using DVD Fab, I was able to break the region 4 coding (without changing the region on the dvd drive) and copy the .vob file to my hard drive. Once these files are on your hard drive, the region coding is gone as well as the copy protection, but is still in the PAL format.
I then opened Powerdirector 8 and imported the .vob files. Before doing anything else, I changed the properties of the project to PAL (you MUST do this). Then I clicked and dragged the video files in order on the timeline. I was then able to edit, add chapters, or do anything I wanted so the final DVD fits my needs. Once I was finished, I clicked "Create Disc" and designed a menu. Make sure you check you settings for burning a DVD and make sure you are burning to an NTSC USA DVD (in the settings). After all that save, then burn. It will convert the video to NTSC (might take an hour or two) then burn to DVD.
This works very well, clear picture, and user customized.