Hasta La Motion!

I’m using NukeX 6.0v3 and Im noticing that after creating a shape in rotopaint, if i move forward or backward in the timeline, the splines/outlines of the shape shift dramatically across the frame, away from where I’ve put them. However, if I look at the alpha channel, the shape is exactly where I put it. Switching back to the RGB channel, my splines are once again in the right place. This continuously happens as I go through the timeline. The viewer displays my rotoshape somewhere that it is not and I have to toggle the alpha channel on and off for the viewer to display it properly. Please help. This is extrememly annoying.