Why is Map-IP inaccurate on some locations?

The firstly we do not control the geo data. It is provided by NetGeo. Secondly, when plotting, NetGeo just gets the location of your ISP. Accuracy should be high if you are using 56k or very low if you live in a large country such as the US or if you use high-speed internet access such as DSL or Cable. The lat/lon coordinates of large websites or universities should be more accurate.

Why do I not see the image of the earth on which the dot is overlayed?

Your browser does not support transparent PNGs. Go to the preferences page and set the "draw mode" to "CSS".

When I install this script on windows, I don't see anything when I open plot.php. or I see a broken image.

Open up plotconf.inc and change the $trygd variable to "0".

When I install it on my server there are much less configuration options than on your server.

You don't have GD installed. You could possibly install it and recompile PHP.

Would it be possible to provide a web traceroute?

Yes, but you can't force a traceroute from another location. That means that if you were doing the traceroute, the traceroute would start at the server the PHP script is installed at, which is completely meaningless to the user.

A PHP traceroute program that you download and just run on localhost is pretty pointless too, as there are much better visual traceroute programs such as xtraceroute, which with a patch also supports NetGeo data.