Err, here's the problem here. Clouds do not cast faint shadows onto the terrain currently. Now this is easiest to see if you turn down the brightness and switch off smooth lighting. When you get close to a current shadow on the terrain, and only when you get close, the shadows start to spread across your world like a virus 1 block at a time. You can be flying directly under a cloud, it won't make a single shadow on your world.
Well, I don't always have clouds around in rl, so it would be different for me having shadows all over the place, then again I also don't have farm animals all over the place either. The thing with the darkness bugs is that it used to be fixed but it lagged us more, so now we don't lag as much but have more lighting issues. I prefer less lag so..