This has been an issue since I started playing (since update 9 or so): whenever I use my laptop to play, the left mouse buttons on my touchpad and portable wireless mouse do not work properly. most of the time (say 9 clicks out of 10,) the button does nothing, and when it does work, it gets stuck, so I'm just constantly firing until I mash the LMB enough to turn it off. The right and middle mouse buttons work as they should.