Solution or Workaround
The problem is with the continent of Antarctica spanning the grid. There is an imaginary grid that goes from west -180 degrees to east 180 degrees. When Atlas tries to draw Antarctica, after its Admin98 is converted from a shapefile to a geo file, the continent cannot wrap around from the east side of the grid to the west side of the grid.
The only way to see both files together in Atlas GIS is to create two separate shape files and convert each one to a geo file. The following will help to accomplish this:
1. Open the Admin98.shp file in ArcView.
2. Select Antarctica and save it as a shapefile.
3. Select the rest of the world's countries and save them as a shapefile.
4. Open Atlas GIS and convert each new shapefile in Atlas.