Pixels in Transitions

[Jill Arenson]

I've completed a project (video) using FCP4 (on a new G5) and outputted 
a Quicktime DV/DVC Pro - NTSC size 720 X 540  Quality: Best, Sound 44.1 
kHz.  I did "render" the project in its entirety (sound and video) 
before exporting.

The DV file plays and sounds beautiful in QuickTime.  All transitions 
are perfect.

I created a DVD of the DV file using iDVD 4.  The DVD burned with no 
problem.  However, when I played the DVD on a DVD player and on my 
computer, there are three spots where during the transitions a brief 
flash of pixels appear rather than the transition.  It happens only 
three times in probably 50 transitions.   The transition used was 
"Dissolve" where the pixels appear- but this transition was used 
frequently and in other places had no problem..  I did use some more 
flashy/complicated transitions a couple of times, but those were not 
affected.

I recall seeing some discussion regarding pixelation during 
transitions, but I seem to remember that discussion centered around 
still photos.  All clips used in this project were video, no stills at 
all.

Is this a problem caused by iDVD?  Did I miss some setting in iDVD?  I 
recorded the DVD using the setting "Best Performance", should I have 
used "Best Quality"?

Or - is there something I should be looking for or doing in my  FCP 
project before exporting?

I'm thinking of taking the DV file and transferring it to my PC and 
trying to burn a DVD using DVDit.

Any hints or suggestions for possible the cause/resolution would be 
greatly appreciated.

Jill