[lubuntu] Function keys stop working on AC power or after reboot

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http://ubuntuforums.org – Hi, I am using Lubuntu 12.10 64-bit on a new Toshiba Satellite L840D laptop. I am having a problem with keyboard shortcuts that use the function keys: F9 to decrease volume, Alt-F4 to close windows, etc. Most of the time, these shortcuts work fine. However, they stop working altogether whenever I either wake up from suspend or plug in the power cord. This problem doesn't happen if the power cord is in when I turn the computer on - only when I insert the cord after it has been running on battery, and it doesn't happen when I wake up from hibernate - only from suspend. The problem disappears (Hardware)