hi there
had the same problem, but with the help from this thread i managed to get the wheel to work.

use this config for your Xf86-config-4, as jgmcbride wrote above:
Code:
Section "InputDevice" 
 Identifier "Configured Mouse" 
 Driver "mouse" 
 Option "CorePointer" 
 Option "Device" "/dev/psaux" 
 Option "Protocol" "ImPS/2" 
 Option "Buttons" "3" 
 Option "ZAxisMapping" "4 5" 
EndSection
then, and this is the part which was missing in this thread, change the first lines of your config file to something like this:


Code:
Section "ServerLayout"
        Identifier     "XFree86 Configured"
        Screen      0  "Screen0" 0 0
        InputDevice    "Keyboard0" "CoreKeyboard"
        #InputDevice    "PS/2 Mouse" "CorePointer"  <=this was the original one
        InputDevice "Configured Mouse" "CorePointer"  <=change to the "configured mouse"
restart your x-server and it should work fine...

greetings
D