I'm using jScrollPane to create a custom scroll bar style.
View my current code here: http://cwhitaker.com/deck/deck.html
The jScrollPane works in all modern browsers, but the ability to scroll only works in Webkit browsers (Safari & Chrome). Although in the jScrollPane demos the mouse scroll is fully functional in all browsers.
Maybe it has something to do with my columns using absolute position?
For me, the scroll bars were not working with mouse scroll on any browser on the referred webpage.
I copied the entire HTML, CSS and JavaScript code from the webpage referred to in the question to http://jsfiddle.net/ytQMs/. After making the following changes I was able to get mouse scroll working on all browsers:
I suggest making these changes in your code and trying out.