I fixed the problem. Looks like I am pressing Shift button for time more than 10 seconds, when I thinking. Slow Keys are enabled after such type of Shift pressing. Accessibility and Show Keys are denied in my system, but because of bugs in some desktop environments (such as xfce4), these settings are ignored. So solution is to add such script in autostart after graphical login to Xfce:
xkbset -sl # Disable slow keys (if already active). xkbset -a # Disable accessibility to prevent it from switching on. Don't forget to install xkbset before this. Related bugs with this problem, where you can found discussion of the problem: https://bugs.launchpad.net/ubuntu/+bug/1002951 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=677173 https://bugzilla.redhat.com/show_bug.cgi?id=816764 To detect problem existance in your system dissable Accessibility in gui setting and then run: xkbset q | grep "Accessibility Features" Solution is from here: https://www.unix-ag.uni-kl.de/~guenther/slow-keys.html If "On" then you have the problem. ** Bug watch added: Debian Bug tracker #677173 http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=677173 ** Bug watch added: Red Hat Bugzilla #816764 https://bugzilla.redhat.com/show_bug.cgi?id=816764 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1350580 Title: Keyboard freezes after some random time To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-input-evdev/+bug/1350580/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
