If you got it working through xorg.conf then you probably don't want to do anything... but in Ubuntu 8.10 the mouse is not handled in xorg.conf anymore (and that's why you didn't see anything there) but rather through HAL.
To execute what's written in that page you would need to:
1. Open a terminal window
-> click Alt + F2 and then type Terminal and press Enter.
2. Move to the right folder
-> type: cd/etc/hal/fdi/policy/ and press enter
3. Create the file and edit it. It's a restricted folder which your user can't write into, so you need to run it as root (which is what sudo does. Do I need to warn you about using sudo?):
Ubuntu:
-> sudo gedit mouse-wheel.fdi
Kubuntu:
-> sudo kate mouse-wheel.fdi
You will be asked for your password and then a text editor very similar to notepad in Windows (just more advanced) will open. Copy the text from the link into gedit or kate, save and close the window and choose to save. You will then have to reboot your laptop for the HAL settings to take effect.
If I flub- will it be easy to correct?
Well, you can make it easy to correct...
Before you edit xorg.conf and other important system files make a copy of them. In terminal you copy like that:
cp filename_to_copy new_filename
or: cp xorg.conf xorg.back_up (or even better, put the date/time stamp in the filename)
For file operations under /etc/X11 you will need to work as root by using sudo.
Then if something goes wrong you have a backup file.
But if something does go wrong with xorg.conf you will probably have to use command line so it's good to learn some basic commands (and how to use nano instead of gedit or kate);
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Again, you might want to leave things as they are if they work, but for from 8.10 this is the correct way to get the trackpoint scroll working in Ubuntu.
Hope this helps... even if not right now.
Edit: deleting extra space.