Comment 107 for bug 868400

That might be related:

https://bugs.launchpad.net/ubuntu/+source/gnome-settings-daemon/+bug/801763
Typing causes cursor to stick

This bag fix introduced 0.5 sec delay in gsd instead of 2.0

* debian/patches/10_smaller_syndaemon_timeout.patch:
    - Use a smaller timeout for syndaemon (LP: #801763)

Relevant upstream gnome code is located at:
http://git.gnome.org/browse/gnome-settings-daemon/tree/plugins/mouse/gsd-mouse-manager.c#n504

I have that 2 syndaemon issue once in a while, but can not reproduce it fast. If somebody wants to test if increasing delay fixes the bug, look at
http://ubuntuwiki.net/index.php/Touchpad,_disabling_while_typing

The modified command to execute:
syndaemon -i 2.0 -K -R