Bug#452121: xserver-xorg: keyboard stops working
I believe I may have found the source of this bug. Based on Ronald's
comments about the deletion of configuration directories fixing the
problem, I did a little process of elimination to determine which
directory needed to be deleted to make the keyboard work again. It
turned out to be just the ~/.gconf directory.
Furthermore, I discovered that even without deleting the entire ~/.gconf
directory, I could make the keyboard work again by disabling Slow Keys
by editing ~/.gconf/%gconf-tree.xml and setting the value for
"slowkeys_enable" to "false" within the keyboard accessibility section.
When my keyboard had originally stopped working, I was using an
application in which I held down a modifier key for a length of time,
and the Slow Keys dialog box popped up occasionally. My guess is that I
somehow inadvertently enabled Slow Keys, which prevented the keyboard
from working from that point forward. Then, once I hand-hacked
%gconf-tree.xml as described above to disable Slow Keys, then the
keyboard worked again the next time I restarted xorg.