I am using the Live/DVD of LMDE 64 bit and the touchpad has no tab under the mouse preferences so side scrolling doesn't work, plus you can not disable the touchpad when typing nor disable the tapping. As I recall it was this way in in LMDE RC1 as well as Debain when I tried it. I was hoping that it was fixed in this version.
I believe I used an fdi file to set the touchpad prameters in previous versions.

