I had been facing the same problem in Kubuntu Feisty Fawn, and got it
solved as follows (courtesy goes to ubuntuguide.org):

This disables the touchpad while typing:
First edit |/etc/X11/xorg.conf| to allow the |syndaemon| utility to
access the touchpad's settings -
sudo gedit /etc/X11/xorg.conf

Find the touchpad section:

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

Add the |SHMConfig| option if it does not already exist.
After restarting X (log out and log in again), you will be able to run
|syndaemon|.
syndaemon -t -d
You may have to restart your computer.

To have |syndaemon| start up automatically when you log on, add the
command as a new startup program (System -> Preferences -> Sessions ->
Startup Programs).