Comment 33 for bug 320632

you can do something like this:
sudo apt-get install xserver-xorg-input-synaptic=0.15.2-0ubuntu8

If it doesn't work you can get the deb package and install it manually

Also, can you attach the output of this command again (after settings the values which work for you)?
xinput list-props 7

replace 7 with the identifier of your synaptic device.