Description of problem:
Without any particular reason, X on F-9 sometimes suddenly changes keyboard
behaviour.  Normally, when I press a key, the character pattern is as follows:
  (press) x (delay) xxxxxxxxx (release)
After the spurious change, the behaviour changes to this:
  (press) (delay) xxxxxxxxxxxx (release)
I never manage to press the key just long enough to emit one character, the
minimum I achieved was two.  This leads me to suspicion that two chars are
actually emitted when the repeating pattern occurs.

Control keys (alt, ctrl) behave yet differently.  X server takes time to notice
that the key is held, but then refuses to release it.  Hence as soon as I press
alt, I can not use backspace, otherwise whole X session goes awol, which is a
typical way such sessions end, because I can never quite keep myself from
pressing backspace instinctively.

Mouse is not affected by this problem.

The keyboard is dell-branded SK-8115.

It has never happened to me on F-8.

Version-Release number of selected component (if applicable):
xorg-x11-server-Xorg-1.4.99.902-3.20080612.fc9.i386
xorg-x11-drv-keyboard-1.3.0-3.fc9.i386

How reproducible:
Not very well.  Today it already happened twice, before that the system was on
for a week without a problem.

Steps to Reproduce:
Sorry, no idea.
  
Additional info:
I'll attach relevant logs in a minute.
I'll try to run xorg.conf-less when it happens next, I don't really need
accented characters for my work.
It seems to me that bug 450249 could be related.