Admittedly I am a Slackware user but the problem looks the same. I fixed it using the advice at:
http://rooster.stanford.edu/%7Eben/toshiba/keyboard.php to paraphrase: install accessx then run the commands: ax +bouncekeys ax -timeout ax bouncedelay 10 worked a treat for me. Another method, based on the same reasoning is covered at: http://www.janerob.com/rob/ts5100/index.shtml -- Keyboard random repeat and dropped key presses https://launchpad.net/bugs/39315 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
