Model 15t-j100. This is a physical issue not driver/software. Occasionally the touchpad won't click (usually it's the right side but sometimes it's the left). When it gets in this state there is no tactile click or audible click. Most of the time if you press hard it will register, but now the right-side won't register no matter how hard I press. The touchpad usually comes back to normal after a couple of days. Is there some kind of pad under the touchpad that can get displaced (The case has come apart at one of the hinges. See http://forum.notebookreview.com/threads/envy-case-is-coming-apart-close-to-the-left-hinge.826678/ )? How can I fix this? TIA EDIT: Mystery solved. Broken pieces of plastic had gathered under the touchpad preventing the click.