I have the same issue and the trigger seemed to be moving from an AMD to an Nvidia graphics card. Switching to console (CTRL Alt F1) and back fixes it but can cause some issues with any graphical applications running at the time. I am also using the Ubuntu automatic Nvidia driver that appears to currently be one version behind the one on their website.
-- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1316873 Title: Left mouse button stops working To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1316873/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp