RH 9 XF86Config has different format than AP81 mentioned then(original one):
Section "InputDevice"
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "IMPS/2"
Option "Device" "/dev/psaux"
Option "ZAxisMapping" "4 5"
Option "Emulate3Buttons" "no"("no" change to "yes"
EndSection
Identifier "DevInputMice"
# If the normal CorePointer mouse is not a USB mouse then
# this input device can be used in AlwaysCore mode to let you
# also use USB mice at the same time.
Driver "mouse"
Option "Protocol" "IMPS/2"
Option "Device" "/dev/input/mice"
Option "ZAxisMapping" "4 5"
Option ""Emulate3Buttons" "no"("no" change to "yes"

EndSection
After doing these changes, still not 3-key mouse. I don't see "Emulate3Timeout" option.