Help compiling a new widget

[Mathew Yeates <mathew yeates tv>]

Hi

I wanted to make a widget that is a variation on GtkSrolledWindow. After 
creating a library with my new widget in it, when I link to my library I 
get the error
unresolved external symbol __gtk_marshal_VOID__ENUM_BOOLEAN
unresolved external symbol __gtk_widget_get_aux_info
unresolved external symbol __gtk_range_get_wheel_delta

I've looked around but I can't seem to find a library containiong these 
functions. I see that  _gtk_range_get_wheel_delta is defined in 
gtkrange.c but it doesnt show up inside libgtk.

Any help??

Mathew