I just installed Hiweed, an Ubuntu based distributed edition on my ThinkPad T43 yesterday. Unfortunately, track point can not scroll with the blue middle button. But fortunately, there is a solution. According to this guide, add the following lines in "/etc/X11/xorg.conf" and comment the original. After reboot, scrolling works.
Section "InputDevice"
Identifier "Configured Mouse"
Driver "mouse"
Option "CorePointer"
Option "Device" "/dev/input/mice"
Option "Protocol" "ExplorerPS/2"
Option "Emulate3Buttons" "on"
Option "Emulate3TimeOut" "50"
Option "EmulateWheel" "on"
Option "EmulateWheelTimeOut" "200"
Option "EmulateWheelButton" "2"
Option "YAxisMapping" "4 5"
Option "XAxisMapping" "6 7"
Option "ZAxisMapping" "4 5"
EndSection
