In addition to what Mona said, you can set your default scale method as follows (by editing your preferences).
Edit | Preferences | Show Defaults, Default Image Settings: Scaling. Select the scale method you want to use as your default scale from the dropdown list.
Side Note (nitnoid factoid):
Default Image Settings should actually be
Default Layer Settings since you're actually setting the default scale for any layer you create (by adding a gradient or solid layer, adding an image or graphic or video, etc).
Dale
PS You might want to read the following:
http://fpvp.wordpress.com/proshow-discu ... ge-import/It discusses each of the scale options.
After that, you might want to review this:
http://fpvp.wordpress.com/proshow-discu ... tionships/It tells you how to calculate the width and height of a layer ... that way, you know how much is extending beyond the frame or how much of the frame isn't being used. It gives you a good idea about how much you may need to pan the layer down or up or sideways ... or how much is necessary to crop away to set the layer to the same size as the screen (if that is what you feel a need to do).