I open a PDF document. It's a document I've created. I have my trackpad set on "tap to click" from the trackpad system preferences. Right now the tap with one finger doesn't work when I have the PDF document open. Physically clicking with the trackpad doesn't work. The two-finger tap for a right click works. Physically clicking in the area of the trackpad that signifies a right click works. No left click works. This is true for all PDFs I open. This is true for any file I open with TextEdit. Everything works fine in Chrome, Safari, Mathematica, etc.
Any suggestions would be greatly appreciated. I have tried this with a mouse since I don't have a mouse. I'm using a Macbook Air 11" late 2011 model running Lion.