Very Specific Arrow Key Malfunction in Xfce Since Kernel 3.2

[Gilbert Sullivan]

I'm guessing that this is a keyboard or motherboard driver issue, but
the behavior is so very odd and specific just to a single function in
Xfce, that I thought I should mention it here -- just in case someone
can suggest troubleshooting steps.

Since the 3.2 kernel version upgrade, my Lenovo T520i running the AMD64
version of Debian testing exhibits odd behavior of its arrow keys. When
I hit <Alt>+<Space> to bring up the window menu on the window with
focus, and then choose <M> to enable movement of the window, the arrow
keys work very erratically in directing window motion.

Instead of moving as expected the window will jump up and down when I'm
trying to move it side-to-side. Sometimes the window will jump halfway
off the screen, and then the arrow keys will lose their ability to make
it move at all. The mouse is always able to move the window properly.

This is the *only* case in which the arrow keys cause unwarranted
behavior. They function perfectly for moving a cursor through text or in
spreadsheets, and they even function normally if I turn on mouse emulation.

Let me explain what little I've done so far in the way of troubleshooting.

1. I checked to be certain that the behavior is the same in other user
profiles. It is.

2. I checked with several different keyboards to see if the behavior
varies from keyboard to keyboard. It doesn't.

3. I've checked to see if the behavior varies from session to session.
It does, slightly. If the arrow keys lose the ability to move a window
after it jumps halfway off the top of the screen, then that behavior
will continue every time the arrow keys are used at least until the
system is rebooted. Logging out and back on has no effect on arrow key
behavior. Once the system is rebooted it may exhibit the same behavior,
or the windows may jump up and down but not lose the ability to be
controlled in some manner by the arrow keys. In that case, I can always
eventually jockey the window to the desired position. Again, this
behavior will continue in exactly this manner at least until the next
reboot. (Hey, I did say it was weird, didn't I?)

4. I've changed keyboard layouts a number of times. That has no
discernible effect upon the issue.

If someone can suggest troubleshooting steps or what package I might
file a bug against (and, perhaps, the most efficacious method of filing
such a bug report), I'd appreciate it.

Regards,
Gilbert