There is a bug if you add more than 9 pages, when you move to the 10th page it jumps to the 11th page, causing the whole thing to break eventually.
You can easily replicate this if you simply add more colors to the demo here: http://joehewitt.github.com/scrollability/example2.html
Try increasing the array of colors to 12.
I’m trying to debug the source, I’ll post here if I can find anything.