I believe that problem comes from the wrap and items. After some testing I've managed to create something that solved my problem - if the items selector is the same as the root selector than it works.
var selector = "my jQuery selector";
$(selector).scrollable({
vertical: true,
items: selector
});
Another thing that you should note is the problem with the getSize function
getSize: function() {
return wrap.children().size();
}
The wrap childrens may be more than just the items that we want to scroll. for example
<ul>
<li><a href="google.co.il">Google</a></li>
<li><div class="box">some text here</div></li>
<li><img src="image.jpg" /></li>
</ul>
The size is 3 but if we will use the getSize function the result will be 6. Instead of wrap.children().size() you should use items.size() and that should give us the wanted results (Assuming that the problem that I've mentioned above will be fixed)