After sitting idle for 20 minutes my computer shows a larger then normal acct. picture with the word "locked" and "switch user". All I have to do is click onto the acct. picture (just like i normally would when logging on) and it will go back to wherever i was, no matter where that was. I don't know why it's doing it , but I don't imagine it's a good thing , it's even a little bit scary to see. Can any body recomend a solution to stopping this revolting development ?