Hi Recently, I have had this problem when my system logs off automatically. Usually in the middle of using VLC (most probably moving the window from one place to another), it just logs off. No error or anything else is shown. I could relogin and start my work normally. Have restarted my computer after the second incident but the problem still persisted. Any idead why this could be so?? I have a MacBook Pro 3,1 2.2 GHz. 4GB RAM and 500 GB Seagate 7200 ST9500420AS hard drive. Thanks for the help.