Section "InputDevice"
	Identifier	"Synaptics Touchpad"
	Driver		"synaptics"
	Option		"SendCoreEvents"	"true"
	Option		"Device"		"/dev/psaux"
	Option		"Protocol"		"auto-dev"
	Option		"HorizScrollDelta"	"0"
EndSection

there is one other instance of synaptics farthere down. here it is:

Section "ServerLayout"
	Identifier	"Default Layout"
	Screen		"Default Screen"
	InputDevice	"Generic Keyboard"
	InputDevice	"Configured Mouse"
	InputDevice     "stylus" "SendCoreEvents"
	InputDevice     "cursor" "SendCoreEvents"
	InputDevice     "eraser" "SendCoreEvents"
	InputDevice	"Synaptics Touchpad"
EndSection