Why isn't Lou Wagner credit listed on IMDb?

Now this may be a topic only I care about but I remember as soon as I saw the principal at the Harvest Dance, I immediately recognised him from somewhere. Eventually I remembered I saw him on an episode of My Name Is Earl. But when I went to Lou Wagner's IMDb page and his credit isn't listed at all. Does anyone know how you might be able to add him or why it isn't there? inb4 someone says "It's because this film sucks". I quite liked it, sorta like a mixture between Better Off Dead and Napoleon Dynamite.