Super Weird Mouse Problem! Help!

My left mouse button randomly decided to stop working last night. I was drawing a box on y desktop and then boom - nothing. The right mousr button works fine. THe scroll wheel works fine and it points just fine. There are no drivers involved as I have a plug and play mouse and keyboard, which have worked great for almost a year. None of the settings in the control panel have chaged. I tried restarting and even tried a system restore to no avail. Wha the f*uck is going on!