Operating system:
Gnome-Commander 1.2.8.5
Ubuntu 9.10
Linux ubuntu 2.6.31-19-generic #56-Ubuntu SMP

Steps to reproduce:
1. Open Gnome-Commander
2. Open the Bookmarks window (defaul: Ctrl+d)
3. Double-click on one of the bookmarks

I've checked the src/gnome-cmd-bookmark-dialog.cc.
In the on_dir_selected() function (line 337) the update_move_buttons() is called after the if-else. This is not ok, because he if branch calls on_dir_goto() which will destroy the window. I've moved the update_move_buttons() in the else branch and the bug seems to be fixed.

Old code:

    if (event && event->type == GDK_2BUTTON_PRESS)
        on_dir_goto (NULL, dialog);
    else
    {
        dialog->priv->sel_bookmark = (GnomeCmdBookmark *)              gtk_clist_get_row_data (list, row);
        gtk_widget_set_sensitive (dialog->priv->remove_btn, TRUE);
        gtk_widget_set_sensitive (dialog->priv->edit_btn, TRUE);
        gtk_widget_set_sensitive (dialog->priv->goto_btn, TRUE);
    }
    update_move_buttons (dialog, row);

New Code:

    if (event && event->type == GDK_2BUTTON_PRESS)
        on_dir_goto (NULL, dialog);
    else
    {
        dialog->priv->sel_bookmark = (GnomeCmdBookmark *) gtk_clist_get_row_data (list, row);
        gtk_widget_set_sensitive (dialog->priv->remove_btn, TRUE);
        gtk_widget_set_sensitive (dialog->priv->edit_btn, TRUE);
        gtk_widget_set_sensitive (dialog->priv->goto_btn, TRUE);
        update_move_buttons (dialog, row);
    }