Windows 7 makes me login after going idle?

When I don't use my computer for a certain amount of time, the screen goes black. When I come back to the computer, it makes me log back into Windows. In the screen saver options, "On resume, display logon screen" is UNchecked.This is a brand new computer that I just set up yesterday, so I'm still trying to get back the initial settings. Thanks for any help.