Fixing text and vectors to export to quicktime

I have been working on a simple presentation for a hotel that shows its meeting rooms and some food shots to be played on a loop in their lobby. The problem I am running into is this…I test published this movie all monring, just for proofing an approvals and such. Just now, 2:30pm I publish another “proof” and the scrolling text that introduces sections of the movie is now not rendering right. It moves correctly across the screen but the outside edges are jumpy/flickering like it is trying to interpolate or something.
I am exporting to Quicktime using the Animation compression, 24 bit color, and 100% quality. Also I am scaling the piece down from 800x600 to 640x480 to fit into iDVD. Like I said though, earlier today, no problems…now, messed up text and vector artwork (hotel logo was imported from Illustrator so it could scale if necessary) everything else in it is fine. I just did an export at full 800x600 and the problem went away, but I need it at the 640x480 size and had no problems with it earlier.
Just for clarification…all my text is still text, not images, so it isn’t a pixelation issue. Attached are two screen shots. The first is from this morning’s export, the second is from later in the day, 3-ish.