Contour plots generate empty plot region

// Change the end of line delimiter 
#d ;

// Generate the theme file used to simulate ggplot2 aesthetics
brewtheme ggtheme, numticks("major 5" "horizontal_major 5" "vertical_major 5"     
"horizontal_minor 10" "vertical_minor 10") color("plotregion gs15"              
"matrix_plotregion gs15" "background gs15" "textbox gs15" "legend gs15"         
"box gs15" "mat_label_box gs15" "text_option_fill gs15" "clegend gs15"          
"histback gs15" "pboxlabelfill gs15" "plabelfill gs15" "pmarkbkfill gs15"        
"pmarkback gs15") linew("major_grid medthick" "minor_grid thin" "legend medium"    
"clegend medium") clockdir("legend_position 3") yesno("draw_major_grid yes"     
"draw_minor_grid yes" "legend_force_draw yes" "legend_force_nodraw no"          
"draw_minor_vgrid yes" "draw_minor_hgrid yes" "extend_grid_low yes"             
"extend_grid_high yes" "extend_axes_low no" "extend_axes_high no")              
gridsty("minor minor") axissty("horizontal_default horizontal_withgrid"         
"vertical_default vertical_withgrid") linepattern("major_grid solid"            
"minor_grid solid") linesty("major_grid major_grid" "minor_grid minor_grid")     
ticksty("minor minor_notick" "minor_notick minor_notick")                       
ticksetsty("minor_vert_default minor_vert_wgridnolab") gsize("minortick_label minuscule"            
"minortick tiny") numsty("legend_cols 1" "legend_rows 0" "zyx2rows 0" "zyx2cols 1")                         
verticaltext("legend top");

// Change end of line delimiter back to carriage return
#d cr

// Now five colors from same palette using the ggplot2 inspired theme
brewscheme, scheme(ggplot2ex1) allsty(ggplot2) allc(5)  ///   
themef(ggtheme)

// Load example data
sysuse sandstone.dta, clear

// Create contour plot with brewscheme generated scheme file
tw contour depth northing easting, scheme(ggplot2ex1)
Results in the plot region being empty.
wbuchanan / brewscheme

Contour plots generate empty plot region #33
