Anyone have experience w/ DVD-R movies working on consumer players?

I am having a problem w/ a system where the projector's image somtimes is jittery... rips, or even loses lock entirely.

VIDEO> Integra Research RDV-1 out YPrPb
Integra Research RDC-7 YPrPb switching
Marantz VP12S1 approx 100' from head end

Phenomena happens more on DVD 480p out, but still happens fequently on 480i out.

Projector exhibits same problem, even when run composite video in.

My one theory is that there is something wrong with the sync component. Would stripping the sync from the Y-component and then reinserting NTSC sync from some sort of combiner fix this problem? Obviously this would only work on the 480i output mode.