That is very low resolution, and that might be the problem. It is possible that some of the fonts that calibre (and google earth) use won't render (display) correctly.
Is it possible to change it to (say) 1024x768? I know that doing so will make the characters smaller and harder to read, but it might fix the problem with calibre. If it does, then a) we know something new about calibre, b) you have a work around, and c) you could choose to get a larger monitor.
