For whatever reason, I've never been able to use my Asus' touchpad to scroll pages in Firefox; when I try virtual scrolling in Firefox, only the mouse pointer changes to a scrollbar. It hadn't particularly annoyed me until I decided to use my touchpad more. The most recent driver from the Asus web site didn't support Firefox but the generic 8.3.4 driver from Synaptics worked.
I didn't realise until I enabled virtual scrolling for Firefox that the feature worked like turning the mouse wheel. For instance, if I hold down the Control key while scrolling vertically, the page's font size changes.