Color correction doesn't work.

Hi,

This question (I think) concerns the correct/incorrect use of the FCS. I tried to apply some basic color corrections to my project, through the tools of the Final Cut (NOT de Color Plug in). Apparently it worked. I saved the project, I made the movie (*mov) and so on.

After that, you know, there are always things that you want to correct again, so I re-opened the same project to "continue" working on it. I tried to apply the color correction again and it did not work, The video filter menu is available but the color correction interface didn't open easily just with double click, I got to open it clicking other tabs.

Ok, the interface was there, I moved the cursors of white, black, whatever but NOTHING happened. I tried to correct what I see in the CANVAS of course because that's what I care, but the correction worked for the PREVIEW "monitor" (window) and not for the Canvas. Why?

And if you don't mind I have another picky question. Is it possible select one section or area of a clip to apply color correction ONLY to that selected area, like you do in photoshop or other design softwares?

Thanks a lo