Just bought a MacBook Air. 5 days later, a very strange problem with the trackpad surfaces. It won't allow me to "click" anything anymore. Weirdly, most of the other functions are still working properly : - Scrolling still works; - Two finger tap sill brings up a contextual menu; - Gestures work fine. Everything works, except the single most important function : clicking!!! Neither clicking nor single finger tapping will work. I tried plugging in a wired Apple mouse. To no avail : I can control the cursor, but clicking won't work! I also tried resetting the System Management Controller (SMC), as well as the PRAM and NVRAM. Didn't help either. Anyone has an idea as to how I might resolve such an issue? Thanks in advance for your help!