Ha, my grandson is 5 years old. While he's way too analytically gifted for his own good, I don't think I coulld explain this to him.
Gonna give it a shot, though.
If you first open the VS2008 BuildAll project in VS2010, it will moan about many things. The only thing you need to fix is the line
families = System.Drawing.FontFamily.GetFamilies(graphics.gfx);
in XFontFamily.CS, because the GetFamilies method from the System.Drawing.FontFamily namespace is now obsolete.
If you change that into
families = System.Drawing.FontFamily.Families;
the BuildAll project will build like no tomorrow.
Alternatively, there is a compiler option "Treat warnings as errors". Turn that off, and it SHOULD still work (I haven't tried that...).
You can then reference the built project for your other projects.
cheers,
peter