Comment # 23 on bug 1200983 from Michael Hirmke

The situation even got worse after installing the latest snapshots.
Now the keyboard stops working while logged into an X11 session. You are typing
some text und suddenly the keyboard does either stop completely or gets
extremly slow, i.e. one keypress every 10 seconds.
If this happens, it doesn't help to switch to a different keyboard and/or
connect the keyboard to a different port.
Switching to the console with Alt-F2 works, though, and in this situation
typing in a console window also works without any problem. Back to the X11
session the keyboard is still dead there.
The mouse is not affected in this situation.

I'm not sure if this is another incarnation of the same problem or a different
one.