Hi,
Our "Product Fancy Slider" has been redesigned (from scratch) recently.
The new version shouldn't cause that problem at all.
I just sent you the new version's download link.
I know it would be an extra work for you since i am seeing you did lots of customizations, but it would worth for it. The new version comes with more advanced features such as "infinite loop" and "auto scrolling".
You can see the live of DEMO of new version from here:
www.flexiblewebdesign.com/virtuemart-2-template-fashionmart/index.php?option=com_content&view=article&id=71&Itemid=489