A friend has a problem with his desktop. The mouse, when simply hovering over a clickable item, immediately executes the command without clicking (i.e., simply placing the mouse cursor over a menu entry activates that command). This just started happening suddenly (according to him).
This only affects his user account, and only in Gnome (and Unity, I believe) and doesn't affect any other user or any other desktop environment. I have reviewed the mouse settings in both Unity and Gnome and they appear to be set no differently than the settings of the other users.
I would think if the mouse settings were in a file (and I have seen by web searches that previous versions of GNOME used the xorg.conf file, though I'm not sure that that's true of 12.04) then I could simply replace the file of this user with the file of a user who isn't experiencing this problem. Any suggestion appreciated.