[nem-en] Gtk not found

[Jim Apple]

when compiling the example at http://nemerle.org/Gtk_text_editor , I get

[~/nemerle/code/gtk text editor]$ ncc SimpleEditor.nemerle
SimpleEditor.nemerle:4:1:4:16: error: unbound type name `MenuItem'
SimpleEditor.nemerle:35:1:35:17: error: unbound type name `Window'
SimpleEditor.nemerle:38:1:38:17: error: unbound type name `TextView'

I assume it's a Gtk problem; I have the base Mono install from 
http://www.mono-project.com/InstallerInstructions .

What am I doing wrong?

Jim Apple