Gtk2::CellRendererMultiline is not registered with gperl as an object

[Jens Wilke <jens wilke org>]

Hi muppet and all,

i copied 
package Mup::MultilineEntry;
package Gtk2::CellRendererMultiline;
without any changes from examples/customrenderer.pl  into my script.

my $renderer = Gtk2::CellRendererMultiline->new;
in package main causes the following error:

Gtk2::CellRendererMultiline is not registered with gperl as an object 
type at /usr/local/bin/gtk-gallery line 193.

How could this error be caused?

Rgds, Jens