[MonoDevelop] "The widget could not be found in any referenced library"

[Adam Tauno Williams]

I have a widget library and then another project that uses that library;
all the widgets from that library work, but one widget is not seen by
the other project:

[Task:File=/home/awilliam/Works/OpenGroupware.NET/factory/Whitemice.ZOGI.GtkFolios/gtk-gui/gui.stetic, Line=0, Column=0, Type=Warning, Priority=Normal, Description=/home/awilliam/Works/OpenGroupware.NET/factory/Whitemice.ZOGI.GtkFolios/gtk-gui/gui.stetic: Could not generate code for widgets of type: Whitemice.ZOGI.GtkForms.EnterpriseQueryForm. The widget could not be found in any referenced library. The generated code may be invalid.]

But in the library widget that class can be browsed,  edited in the
designer,  etc.... AND it used to work but stopped.  Any suggestions on
what I can do to get it working again?    I remember a dialog where I
could select what classes are exported as widgets, but for the life of
me I can't find that dialog anymore.

mono-core-2.2-14.1.i586
gtk-sharp2-2.12.7-22.3.i586
monodevelop-1.9.1-99.6.noarch