This is what I have in my x config for a five button optical,
Code:
Identifier "Mouse1"
Driver "mouse"
Option "Protocol" "ExplorerPS/2"
Option "Device" "/dev/psaux"
Option "Buttons" "7"
Option "ZAxisMapping" "6 7"
And to get the wheel working properly you will need to have a script like this,
Code:
#!/bin/sh
xmodmap -e "pointer = 1 2 3 6 7 4 5"
set to run when you do startx.