I'd suggest changing the image size (whilst retaining the aspect ratio) so the X component is 1440 (it'll be 1440*1080 I believe...), then try cropping it to 1440x900. If it looks as though you're missing too much of the image, lower the Y component of the image size whilst keeping X at 1440 (yes, it'll modify the aspect ratio, but most of the time it's gonna be hard to tell the difference anyway. It'd be an acceptable loss. Keep changing that until it's good enough.
My TV does the same. It's Widescreen, and as well as showing the entire frame with big black borders, there's an option to zoom in a little (with smaller black bands at the left and right), zoom in a lot (so there are no black bands, but it chops a lot off the top and bottom), widescreen mode where it simply stretches it, and 'Super Wide', where it stretches it to widescreen, and makes the frame slightly taller. This way, people don't look so stretched that they look ridiculous, etc.