Had this problem with a samsung touchpad a while back and I found the following worked.
common issues with touch pad being "twitchy" or doing strange things normally comes down to the pressure settings
the problem comes from the touch pad thinking there are 2 fingers so it causes a twitch.
the settings that normally cause this are
PressureMotionMinZ
PressureMotionMaxZ
PressureMotionMinFactor
PressureMotionMaxFactor
I found these were set to low which causes a resting finger to be detected and cause movement.
if that doesn't work then it might be due to the MinSpeed
being to high which is causing the cursor to jump a large number of pixels from a resting finger.
To change settings enter
synclient PressureMotionMinZ=25
into your terminal and it should change the value.
all available variables can be found here
http://www.x.org/archive/X11R7.5/doc/man/man4/synaptics.4.html
just remember to commit your settings to the synaptics.conf
when your done (or edit the values directly in your active conf file)