In my Mouse in Maze animation, the mouse crosses over the blue lines in the java version. I'll try to make the blue lines thicker, it may be a scaling issue.
Thicker lines didn't help, but In watching it, I think the problem has to do with color matching. I take advantage of color matching, and when the two colors hit, the right action doesn't appear to be happening on-line. Hmmm.
Fixed it. Looks like it was an anti-aliasing problem in the whiskers. I had a color over black whisker as an artifact of drawing it. When I redrew the whiskers and reset the colors, all is well.