Than 1000? No, I don't think so. Notice that my test case works with about 400 - 500 FPS, which gives 400 - 500 FPS for Newton. Setting it to 1000 gives two or three times that much FPS (three times because of that +1. It's AT LEAST 1000). It's suspicious that you need at least 1000 FPS, but it does make the difference. You can try lowering it for the test case below GS FPS and you'll see the ball bouncing then.

[EDIT]
Lines
var vratio = (dt * newtonFPS);
var n = integer(vratio) + 1;

can be merged into one line
var n = integer(dt * newtonFPS) + 1;
of course.