I just did a quick search, and this post had an idea that worked for another guy.
Essentially, edit your xorg.conf, using these commands:
Now add the line <Option "SHMConfig" "on">, so it looks like this:
# First back up the original:
sudo cp /etc/X11/xorg.conf /etc/X11/xorg.my.backup
# Now open it for editing:
sudo gedit /etc/X11/xorg.conf
Now, I realize that this example says it's for a Synaptics pad, but the original poster had an alps touchpad, and he claimed this method worked.
Identifier "Synaptics Touchpad"
Option "SendCoreEvents" "true"
Option "Device" "/dev/psaux"
Option "Protocol" "auto-dev"
Option "HorizScrollDelta" "0"
Option "SHMConfig" "on"
Anyways, with this option enabled, you can install syndaemon if it's not on your computer already. This disables your touchpad only when you're typing. For the full list you can just type <syndaemon -h>. Myself, I have it in my startup applications, with these args:
-S forces it to Synclient (lets it run), -t disables only tapping and scrolling (not movement), -d starts it as a daemon, -i is the length of time disabled in seconds.
syndaemon -S -t -d -i 1
Hope this works for you!