problems with Gtk2::ListStore

[Chas Owens <alas wilma widomaker com>]

The following test code works:

<code>
        #!/usr/bin/perl

        use strict;

        use Gtk2;
        use Gnome2;
        use strict;

        use constant VERSION => '0.1';

        Gtk2->init;

        Gnome2::Program->init('test', '0.1', 'libgnomeui');

        my $w = Gnome2::App->new('toplevel');
        my $s = Gtk2::ListStore->new('G::String');

        for (qw(foo bar baz foofoo foobar foobaz)) {
                $s->set($s->append, 0 => $_);
        }

        my $l = Gtk2::TreeView->new($s);
        $l->append_column(
                Gtk2::TreeViewColumn->new_with_attributes(
                        "foo",
                        Gtk2::CellRendererText->new,
                        text => 0
                )
        );

        $w->set_contents($l);

        $w->show_all;

        Gtk2->main;
</code>

but this application code does not:

<code>
        my $store = Gtk2::ListStore->new('G::String');
        for my $dsn (@dbs) {
                $store->set($store->append, 0 => $dsn);
        }

        my $list = Gtk2::TreeView->new($store);
        $list->append_column(
                Gtk2::TreeViewColumn->new_with_attributes(
                        "Databases",
                        Gtk2::CellRendererText->new,
                        text => 0
                )
        );
        $sw->add($list);
</code>

it dies on the $store->set with an error
variable is not of type Gtk2::ListStore at gnome2-sql-editor line 502.

I can see no real difference between the test code and the app code.  Does anyone have an idea?