I've studied LightRoom3 for a few weeks now and I'm really confident with it. (I'm still learning the creative side, but now I know which buttons do what...) But I must have made a few changes perhaps by accidentally hitting a few keystrokes with my command or control button. And this just started happening... When I raise my noise reduction (luminance) Lightroom 3 does not show me a preview of the changes. However, when I change the picture size from FIT to 1:1 ratio, THEN it shows me the effects of my adjustments to the luminance bar. And when I return back to the FIT window screen (as this is the way I normally view my pictures), it returns the picture back to "pre-luminance" adjustment. Thankfully, when I export my pictures, it shows the adjustment. How do I fix this? I've been looking at it all morning.