That, my friend, is chill haze. It happens when the beers get cold and the proteins coagulate and form the haze. Give it a fortnight (love that word!) or so at 40*F and it'll clear right up.
To avoid chill haze:
- Get a strong hot break (from a fast rolling boil)
- Get a good cold break (from chilling your wort very quickly)
- Add irish moss or whilfloc to your boil
All of these techniques help is forcing the proteins that cause chill haze to drop out of solution early on.
Good idea using the gelatin but that mostly just makes the yeast drop out. You need some finings like I mentioned above. But for simplicity's sake, just get that sucker cold for a couple weeks.
EDIT: Are you bottling? If so, you may need to add more yeast due to your gelatin addition