HUD (Heads Up Display) starting up when tap Alt (Default)
$ sudo apt-get install compizconfig-settings-manager$ ccsm # compizconfig-settings-managerfind "Desktop" -> "Ubuntu Unity Plugin" (w/ "Filter" search-box)
uncheck "Ubuntu Unity Plugin"
- click "Ubuntu Unity Plugin"
- search "Key to show the HUD when tapped"
- click button ("<Alt>")
- check disable
- close dialog and ccsm