This time it was the middle mouse button on my IBM ThinkPad X60S. I had got it working following the instructions here in version 10.04 - it just needed a configuration file in /usr/lib/X11/xorg.conf.d.
But it stopped working following the upgrade to Ubuntu 10.10.
It turns out that the xorg.conf.d location has changed to /usr/share/X11/xorg.conf.d.
Putting a file named 20-thinkpad.conf in that directory with the following contents got middle button scrolling working nicely again!
There is talk that it should work by doing:Section "InputClass"Identifier "Trackpoint Wheel Emulation"MatchProduct "TPPS/2 IBM TrackPoint|DualPoint Stick|Synaptics Inc. CompositeTouchPad / TrackPoint"MatchDevicePath "/dev/input/event*"Option "EmulateWheel" "true"Option "EmulateWheelButton" "2"Option "Emulate3Buttons" "false"Option "XAxisMapping" "6 7"Option "YAxisMapping" "4 5"EndSection
But it did not work for me (at least not just like that - tried re-starting xwindows, but still no scrolling - maybe there is some configuration needed, but I like the old way of dropping a file into a configuration directory!