I actually found a temporary solution (it was on ubuntuforums):
1. Install gsynaptics (Touchpad in the "Software Center").
2. Unmark "Disable touchpad while typing" is not marked in "Mouse" (System->Preferences->Mouse->Touchpad).
3. Unmark "Enable touchpad" in "Touchpad" (System->Preferences->Touchpad).
I actually found a temporary solution (it was on ubuntuforums): >Preferences- >Mouse- >Touchpad) . >Preferences- >Touchpad) .
1. Install gsynaptics (Touchpad in the "Software Center").
2. Unmark "Disable touchpad while typing" is not marked in "Mouse" (System-
3. Unmark "Enable touchpad" in "Touchpad" (System-
It worked on 3 machines.