<<<should it flutter between 10 fame>>>
It wouldn't shock me if that was happening because MPEG2 has temporal compression. Only every fifteenth frame or so in an MPEG stream is "real" (the I frames). All the others (the P predictive and B bidirectional frames) are comparisons to each other. In order to do the comparison, the program has to jump around.
<<<I did a dvd burn and the first minute was good then i got big square pixelation 50 minte project high 60 minute encode.>>>
That could be a different problem. Symptoms like that can be caused by poor quality blank disks or very high encode rates. The blank stock check is easy. Buy a five-pack of Sony DVD-R disks and see if the problems don't go away.
If they don't, the problem may be datarate settings. The going theory is never encode over 7 in order not to overload the older DVD players. Some of the DVD Studio Pro High Quality settings go as high as 7.5.
Koz