I have very vanilla hardware and when I just booted the resolution appears lower (icons bigger, jpg's blurry) and the aspect ratio is off (icons are taller than usual).
The screen resolution is currently 960x600, which I don't recall ever having even heard of. If it was 1020xwhatever, which I suspect it probably was, would that information be logged somewhere? It's a built-in video card, but, I guess, could be a hw problem. The monitor settings don't offer a resolution setting. -Thufir

