Why does my Ubuntu desktop screen lock up often?

Your desktop screen automatically locks up when you're not using the computer for 10 minutes. Note that this default feature is for the safety of your computer's data and applications. Website help.ubuntu.com has this say: "Locking your screen prevents other people from accessing your computer while you are away from it. All of your applications and work remain open while the screen is locked, and the screensaver is displayed." You may opt to make the lock-up time grace period longer or disable the lock-up all the way. Assuming you're using Ubuntu 12.04 (Precise Pangolin):

  1. Click on the System Settings in the Unity launcher. (See related image)
  2. With the System Settings window open, look for the icon "Brightness and Lock", click it. (See related image)
  3. Look for the "Turn screen off when inactive for " field. Change the value to you preference. (See related image)
  4. There's the "Lock" field. If you still want the screenlock feature, you may increase the value in the "Lock screen after:" field. Or you may turn it off if you don't like the screenlock at all. Just bear in mind the security implication of the option you use.