I was using iPhoto and all of a sudden a grey screen appeared with multi-language alert asking me to "restart the computer by holding down the power button until it shuts down and turning it back on". After I restart the computer, first thing I notice is the dock reverting back to the original setting. The 4-corner (Expose feature) setting is gone. The language/input setting is reset and everything seems to be reset. It doesn't feel like my Mac. please help How can I get back my normal personal settings like a few minutes ago? I have Time Machine backup, what can I do? thanks a lot in advance.