Gnome configuration, nothing for kde in here...

below are parts of Xorg config file(/etc/X11/xorg.conf however place might be differnet, depends on your Xwindows system)

Section "InputDevice"
Identifier "UsbMouse"
Driver "mouse"
Option "Protocol" "Auto"
Option "Device" "/dev/input/mice"#u can exchange "mice" with some
#particular mouse device, example "/dev/input/mouse0"
Option "Buttons" "9"
Option "ZAxisMapping" "6 7"#dont ask me why,
#dont know why 6 and 7, but when i remap wheel to "right" values
#which is 4 and 5 - side buttons dont work.
EndSection


#ubove is part of your "mouse" device.


InputDevice "UsbMouse" "CorePointer"
#and this goes into your ServerLayout section

#thats all for xorg.conf

than
cd $HOME(guess what is going to happend?)
echo pointer 1 2 3 6 7 4 5 8 9 >> .Xmodmap
!!warning, if u have more than one mouse configured than all others might have problems with it, however my laptop psmouse touchpad worked properly(never used it much anyway, so i dont even know if button change on USB mouse has been reflected on it)

Than boot your gnome and it shall ask some silly question, answere it and enjoy.

BTW, question is, what should i do for both wheels to work?
Never have seen anything usefull about this topic... Anyone?