Hi, guys, I start to use lion on its official release date. However, recently I encounter an issue that the trackpad left click function is missing. When it happens the first time, restart Lion solved the problem. But now the issue persists. I thought it was a hardware issue, but it is not. It is the same for my USB mouse as well. The mouse can move, right click, multi-gestures except left click. So I conclude it is a software problem, so did this issue happen to any one? What is the solution? Thanks.