1440×1080 is supposed to be stretched to 1920×1080 because that’s the size it should be displayed. The difference is the pixel aspect ratio: 1920×1080 uses square pixels with a pixel aspect ratio of 1.0; 1440×1080 uses rectangular pixels so its aspect ratio is 1.333.
If, for some reason you actually do want to change the pixel aspect ratio of the footage, you can right-click the clip in the project window and go to interpret footage > main and change the “pixel aspect ratio” setting at the bottom of the window.
To copy/paste the settings to other clips right-click the clip in the project window that has the settings you want to apply and go to interpret footage > main > remember interpolation (shortcut: ctrl + alt + c). Then select the clips you want to apply the settings to and right-click and go to interpret footage > main > apply interpolation (shortcut: ctrl + alt + v).
Erik Waluska
EAWmedia