Infinite Scroll ?!?!

Hi guys,

i’m new in here. And I have a little problem with the infinite scroll.
I’ve read the tutorial on this page yet, butit doesn’t help me with my Problem.

First the picturetape seems to jump around at the end. And secondly it stops. every time i leave the strip it stops scrolling!?

Would be nice if you can help me.

onClipEvent (load) {
var center = 175;
var speed = 1/10;
}

onClipEvent (enterFrame) {
var center =175;
var distance = _ymouse - center;
if (_xmouse >-32 && _xmouse<32) {
_y +=(distance*speed);
if (_y > 25.4) _y=-650.7;
if (_y < -650.7) _y=25.4;
}
}