Hello, I am on a MBA 2012 with Lion. My 'Finder' stalled so I had to force quit it. Then I decided to restart because it wouldn't actually force quit. This just locked my computer on a grey background, but my mouse still worked. I just couldn't do anything. I just forced shutdown with the power button. (This happened twice before I found out it was my external hdd causing Finder to stall). Anyway, I was wondering if this causes system files to be corrupted like in Windows? I did permission repair and disk check and nothing was abnormal. Thanks for any replies.