Infinite menu speed

Hi, I’m using this swf in a HTML site and it looks great, but when I start the navigation it speeds up a lot! I’ve tried to slow down the maximum speed but it still goes over, and really fast…

This is my code:

onClipEvent (load)
{
   xcenter=232;
   speed = 1/80;
}
onClipEvent (enterFrame)
{
   var distance =0-(_root._xmouse-xcenter);
   _x+=(distance*speed);
   if (_x > 0) _x=-1748;
   if (_x < -1748) _x=0;
}

It’s moving opposite than the original code but this problem was there before I changed it.

How should I solve this bug?

Thanx. ^_~