Left-click not working on trackpad or mouse
My trackpad began malfunctioning suddenly. Instead of clicking, it would click + hold (selecting all text). Very soon after, left-click stopped working. I'm able to navigate with the trackpad, but the click doesn't register (the trackpad does physically click). Sporadically, I have some left-click function with the trackpad and mouse when the computer is awakened from sleep, but not always and never for very long.
When the mouse is plugged in, left-click doesn't register. I disabled the trackpad when the mouse is plugged in under Universal Access, but I still am unable to get the left-click to register with the mouse. I'm able to navigate, scroll and right+click with the mouse. I'm able to left-click when using the mouse keys.
My battery is in good condition (diagnostics were fine and it was replaced last year) and isn't swollen, which I know can be an issue that leads to trackpad problems. A technician saw no problems with the logic board. I am running OS X Lion.
Does this sound like an issue with the trackpad that will be corrected if the trackpad is replaced? Or is it another issue? If the trackpad is disabled when the mouse is plugged in, why is the mouse also having a left-click issue?
MacBook Pro (15-inch Mid 2009), Mac OS X (10.7.5)