Kubuntu Lucid ignoring touchpad tapping settings

I've disabled touchpad tapping under "Keyboard & Mouse" -> Touchpad -> Tapping. Whenever I reboot, though, touchpad tapping starts working all over again. If I go back into the touchpad tapping settings, I can see that the tapping checkbox is unchecked (disabled), yet the tapping is still happening. If I then check and uncheck the box and then hit "apply" the tapping is disabled until I reboot again. (Touchpad tapping had been successfully disabled long before upgrading to Lucid but started again with the upgrade to Lucid).

Another possibly related problem is that sometimes after rebooting, the touchpad settings are grayed out entirely so that I cannot access them at all (right now, for instance). This means I have to logout and/or reboot in order to turn off the touchpad tapping that I've already disabled dozens of times.