Media Encoder and "Jerky" Titles
 

I am using on one computer Premiere Pro 1.5.1, and generally like its output.

HOWEVER, within the last couple months it has been producing output--where the rolling title page visibly jerks up when it scrolls, not the smooth fluid movement at all that I get on the timeline. Does not seem to matter whether that output be a .wmv file or mpeg-2DVD file. Half the time the scrolling title page and ending title page as well, has a "jerky" motion to it.

The rest of the video is beautiful, no errors or jerkiness to it at all. It seems to be something that Premire Pro 1.5.1's Media Encoder is adding, and I cannot figure out what I could be doing wrong! One major customer has seen it and does not care, but I don't want to be releasing product with such a flaw. Has anyone else experienced this? How did you correct it? Any help would sure be appreciated....
SW