I installed LMDE + Xfce on a Dell Latitude D610, and the Touchpad was a real issue for a while until I saw this post. Malligt quoted the below page and cut and pasted the necessary information as I did below. So, thank you very Malligt for posting that information. I am very happy with LMDE + Xfce now because of resolving that isssue. However, I did want to point out that there is a second issue. And, that is that Xfce also sets the Workspaces to be switched by the mouse. So once my Touchpad was working, my Workspaces would switch and disappear seemingly randomly and on a whim. I did not know what was really happening at first, and believed that the Touchpad was simply overly-sensitive. But, this has caused a number of issues that could have been resolved with two simple clicks. To be honest, I do not believe that it is common sense on the part of Xfce. However, I hate to say that because now that I have LMDE + Xfce up and running I am quite happy with it as I said above. But, the truth is that two clicks in
Menu -> Settings -> Window Manager -> Advanced -> Uncheck Wrap Workspaces when the pointer reaches the screen
Menu -> Settings -> Window Manager Tweaks -> Workspaces -> Uncheck Use mouse wheel on the desktop to switch workspaces
would have saved me a lot of headaches and frustration. Anyway thanks again for the post and the info, but I had to add to it in the event that there is someone else out there going through the same headaches.
I hope it helps.
Issues in the Xfce edition
To activate "click on tap" for your touchpad, type sudo gedit /usr/share/X11/xorg.conf.d/50-synaptics.conf and replace the content of the file with the following:
Identifier "touchpad catchall"
Option "TapButton1" "1"
Option "VertEdgeScroll" "1"