Soak the beans and the first green pepper in the water. You could do this overnight. I just threw the beans and the chopped green pepper in the water this morning and left it there till 3:30pm when I came down to start them cooking. I did drain the beans and add new water. That's optional. Just make sure you cover the beans plus 2" of water when you start them cooking.
Bring to a boil, then reduce to a simmer and cook an hour.
At some point during this time saute the second green pepper, onion, and garlic in the olive oil until soft.
After the beans have cooked an hour, add the cooked pepper, onion, and garlic to them. Add the salt, pepper, oregano, sugar, and bay leaf. Cook another hour, covered, at a simmer.
Stir in the vinegar and rum. Cook, covered, another hour.
You're probably left with a lot of broth at this point. Take the cover off and simmer until it thickens up. Use a potato masher to mash up some of the beans to thicken it.