Thanks for your reply.
My code is basically very similar to this telerik radrotator demo here:
http://www.telerik.com/demos/aspnet/Rotator/Examples/Functionality/Scroller/DefaultVB.aspx
The main difference however is that I have changed the images from <img> to <asp:imagebutton>. The javascript I'm using can be seen in the 'ASPX' tab of that page.
Thanks again.