I was logged in via Remote Desktop to one of my Caribbean servers. The browser window was being blocked by the Remote Desktop banner or task bar on top of the screen. I couldn't close it. So I Googled how to close an application window. It said to press Alt + F4.
Well on this stupid Toshiba laptop with the weird keyboard, F4 also needs a function key press as well. The normal key for F4 is to switch display modes when you are connected to a projector.
So I pressed Fn + Alt + F4 and my browser closed. But I must have let go of the Fn key. The cursor froze. The mouse wouldn't work. I am talking about the mouse on the finger pad. It is a Synaptic pointing device. So I shut down the computer and re-started it. No dice. I restarted in Safe Mode. Still had a frozen cursor. Took out the battery, and re-started it with the last good configuration. Nada.
I figured that I had blown the drivers. I went to another machine and did some googling. It said that Toshiba had a mouse lock. It said to press Fn + F9. I did. Nothing happened. I tried Fn + F4. My cursor unlocked.
Hope this helps someone. It sure wasted a bit of my time.