I can't see the screenshots right now, but I think I know what you mean.
When GP4 is set to run in a widescreen resolution (such as 1366x768), it doesn't make the screen wider, instead it cuts the top and bottom of the image to fit the new aspect ratio (You can see this effect quite clearly at the release shots for F1Virtual's 2011 TV style).
There's nothing you can do to avoid this, but if you want the same visual effect as the previous resolution, you'd need to reposition all onboard cameras, cockpit angle etc.
My unfinished tracks: [
www.grandprixgames.org]
Send bug reports and track editing questions to
f1virtualblog@gmail.com