Is your touchpad a synaptic one? If it's the case there is a wrong configuration in your xorg.conf file. Try replacing that with this:
Section "InputDevice" Identifier "Synaptics Touchpad" Driver "synaptics" Option "SendCoreEvents" "true" Option "Device" "/dev/psaux" Option "Protocol" "auto-dev" Option "HorizEdgeScroll" "0" Option "Emulate3Buttons" "true" Option "SHMConfig" "on" EndSection
Is your touchpad a synaptic one? If it's the case there is a wrong configuration in your xorg.conf file. Try replacing that with this:
Section "InputDevice"
Identifier "Synaptics Touchpad"
Driver "synaptics"
Option "SendCoreEvents" "true"
Option "Device" "/dev/psaux"
Option "Protocol" "auto-dev"
Option "HorizEdgeScroll" "0"
Option "Emulate3Buttons" "true"
Option "SHMConfig" "on"
EndSection