1) In Windows Vista the properties files is located in C:\Users\yourusename\AppData\Roaming\PYXIS\WorldView. In XP, it can be found at C:\Documents and Setting\yourusername\AppData\Roaming\PYXIS\WorldView.
2) When you open the properties file to edit it, look for the entry PYXOGRFeature.FilledPolygons=0 and change the value to 1.