Last summer, certain keys on my main Linux machine started doing weird things. It's not clear if it's a problem with the kernel, with KDE, some X11 module, or what. These quirks are reproducible and affect several application in seemingly unrelated ways, but they all appeared at the same time and I suspect are from a common cause.

To catalog all the quirks will be impossible, but here are some of the more common ones interfering with everyday life:

* pgup in kwrite prints a '/' before moving the cursor up, and pgdn causes a menu to pop up.
* In Firefox, if I try to do ctrl-'-' or ctrl-'+' to zoom the text size, the page scrolls down. It ought to stay in the same place.
* The 'end' key in several apps, including filling in text in web forms, such as for this question, may cause a very long pause.
* In RXVT, an xterm-like app I used to like, the up arrow at the bash command line causes 'lpr: Error' to appear in stderr of whatever process initiated it. It should just show me the prior commands in the bash histoyr. The down arrow causes the window manager to do strange things. Things work normal in Konsole and xterm (or maybe there are less noticible quirks I'm forgetting.)

After upgrading everything including the kernel, and uninstalling and reinstalling rxvt, kwrite and other affected software, the problem persists. There are no problems when X is not running, at a regular text-mode conio screens.

Many of the quirks are in KDE applications, but not all. I'd like to blame KDE and use Gnome, but then there are a few quirky apps based on a gtk+/gnome foundation that act quirky.

It's as if certain keys were being interpreted by two separate processes, one the normal one taking the normal actions, and the other misidentifiying keys and invoking other actions.

Maybe I unwittingly installed some horribly written piece of software that hooks into the keyboard handling of X, or fsck'd some /etc config file. I've never seen this problem elsewhere and find no mention of anything like it on any forums or through Google.

Any idea what is happening and how to fix it?

I'm running Arch Linux, rarely more than a month out of date, with icewm but none of the big-name desktops.

It sounds like a possible hardware issue, but then you say it's fine when X isn't running, so that would seem to indicate otherwise. Have you tried a different keyboard just to see if it makes any difference?

I had a weird keyboard issue earlier this week. I quite often use the keypad to enter numbers in various apps (with numlock on). But it refused to work recently making the cursor jump around and entering odd things into the calculator app, etc. I was suspecting a hardware issue but I decided to check the keyboard settings first. I discovered that somehow the "Mouse Keys" had been turned on (I don't remember doing that) and instead of entering numbers it was moving the mouse cursor. I was scratching my head for a while trying to figure out what had happened but it was an easy fix.

If the problem is happening only when Xorg is running, then the keyboard may be misconfigured in Xorg. So, you should try to configure it again.

'xev' may help determine what keys are being misinterpreted.

It's laptop, and my only loose keyboard has the wrong kind of connector. But that reminds me - another oddity is when I run certain programs - oowriter is one - most keys will be doubled or worse. For all the quirks, the letter and digit keys act normal, but when this doubling occurs, typing 'cat' will lead to 'ccccaaaaaatttt' showing in the app. This affects the backspace and delete keys too, so you can imagine the fun of trying to correct this!

Gotta run off to work, but maybe removing and re-installing X is something to try... I'll monkey with config files first, in case I find a specific cause and fix.

This problem comes and goes. It was bad y'day and today, until I closed Open Office just a few minutes ago. The key duplication problem suddenly went away! OO is doing something evil with key event handling that messes up all applications. Workaround for now: never use Open Office!