problem with pagination

hello there all,

i am having a problem with pagination.
the first page looks right, but when i click a link, it redisplays the
same items, and the links at the bottom dissapear.

here is the code

def show_history
        @site = Site.find(params[:id])
        @history_pages, @site.status_changes =
paginate(:status_changes,
                            :conditions => ["site_id = ?", @site.id],
                            :per_page => 10)
end

# in the show_history.rhtml
<%= pagination_links(@history_pages) %>

any ideas ?

thanks