A failure of SkyMap, in both the demonstration and full versions, is the inability of plotting the Milky Way.
José R. Vieira, a Brazilian amateur astronomer, has brilliantly solved this problem by creating a set of files which work as external catalogues and allow the program to plot the Milky Way according to 5 levels of luminosity.
To proceed with the installation, a rather simple task, just download the Zip file and follow the instructions described in the included "ReadMe.wri".