You need to update your library as well because it is missing a new library function. 250-plot.c: 250- replaces libes/gis/plot.c to include G_plot_line2() 250- needed by r.in.poly 250- this library function is found under diretory /grass/grass4.0/updates/src/libes/gis on moon Get those library changes and compile those; then it will work. Lars