I recently added a section to my website that uses the Scrollable JQuery tool to load images from my Flickr account. When I initially load the page the "next" button requires two clicks before it will advance to the next set of images. This only happens on the first attempt following the page load.
When I look at the code it appears that Scrollable fires an event on the first click that removes the "disabled" class on the "prev" anchor tag. It appears to skip the slider event that scrolls the images. You can view the issue here: