jcarousel, problem at 16th click on next button

jcarousel, problem at 16th click on next button

I use jCarousel, with prev/next button as image.

  1.     function mycarousel_initCallback(carousel) {
  2.     jQuery('#mycarousel-next').bind('click', function() {
  3.         carousel.next();
  4.         return false;
  5.     });
  6.     jQuery('#mycarousel-prev').bind('click', function() {
  7.         carousel.prev();
  8.         return false;
  9.     });
  10. };
  11. // Ride the carousel...
  12. jQuery(document).ready(function() {
  13.     jQuery("#mycarousel").jcarousel({
  14.         scroll: 1,
  15.         initCallback: mycarousel_initCallback,
  16.         // This tells jCarousel NOT to autobuild prev/next buttons
  17.         buttonNextHTML: null,
  18.         buttonPrevHTML: null
  19.     });
  20. });


I have 21 image (). If I start to click on next button, all is right until the 16th click. At 16th click on next button, images scrolls back of 3 images.

Any clue?
Alberto