Fri 08-Feb-13 03:47 AM | edited Fri 08-Feb-13 03:48 AM by ShrimpBoy
That exif data appears to show 1/200s at f/10 with -2/3 exposure compensation, and crucially shutter priority mode. Are you sure you didn't accidentally jog the mode dial and end up shooting in the wrong mode? I'm not sure that explains the inability to fire the shutter though, I thought that was usually a result of not acquiring focus when shooting with the AF system in focus-priority mode.
What did you think of the Sigma? I absolutely love mine.