Not so sure but i had such trouble with my DELL Laptop.
After reading
this article
Try to replace InputDevice section in /etc/X11/xorg.conf by the following,
Section "InputDevice"
Identifier "Synaptics Touchpad"
Driver "synaptics"
Option "SendCoreEvents" "true"
Option "Device" "/dev/psaux"
Option "Protocol" "auto-dev"
Option "HorizScrollDelta" "0"
Option "MinSpeed" "0.2"
Option "MaxSpeed" "1.2"
Option "AccelFactor" "0.05"
EndSection
Restart X