Software transcoding tends to be jerky, no matter how good the software is (ie, CCE).
Hardware converters work, but all the ones I have ever seen are either very expensive, limited to VCR decks only, or as they convert to TV signal first, then between the 2 formats - a lossy process.
The reason for the above is simple; digital MPEG2 to digital MPEG2 has no loss issues, but the number of frames per second is different. How do you invent frames to fill in when going from PAL to NTSC without getting jerky? NTSC to PAL you might theoretically get away with, as you would have to throw frames away and smooth out the tweening somehow.
Converting with hardware from digital MPEG2 to modulated PAL or NTSC loses a lot of resolution, but simplifies the process.
The above reasons are why most of us just spend $50-100 on a cheap DVD player that allows hardware conversion to force the output to match the TV, and bypass all regions and RCE encoding. Or take your original DVDs and make them region and RCE free. Then let the player handle it. The hardware conversion from MPEG2 directly to PAL or NTSC is far less lossy. Some players will still be a bit jerky, but not as much as trying to convert with software...