Hmm, no good eyy..
Like you said, it might be adjusted down a bit, if its the drivers side one it will be down a little compaired to the passenger (so it doesnt blind oncoming traffic as much) Park it about 5 meters, or so, away from a wall/garage door/fence and have a geeze, see where they're aimed at..
If they look alright, it could be a bad earth, where it earths to the body/chasis, or bad connection inside the headlight where the bulb goes in, they have waterproof plastic covers over them, that twist into place, if thats not sealing or if its missing, it can corrode the terminals..
Or if its none of that, it could maybe be a dirty reflector/projector thing, if your headlights have been pulled apart to paint them, maybe it got dirty/overspray/something on it?? maybe, even check if the crome is flaking off it..
Hmm, hopefully some of that helps you out mate, let us know how you go this evening..