Open Question: Can a HOA put a lien on my property despite not having knowledge there was a HOA at closing?

When I purchased my property in Dec 2009 in FL it was never disclosed that there was a HOA. Then a few days ago, I get a bill from them. According to my neighbor, there was one at one time a while back but now they want to start it up again. Am I obligated to pay them anything? What can they do legally if I dont pay? Can they actually put a lien on my property? Does anyone have a clue? I do not live in a gated community or condo. I live in a developement that is populated with manufactured homes on property (mine is 2 acres). We all take care of our own land. I did my home work before I purchased and also read all paperwork before I signed. When this was brought up a few days ago, I looked through everthing AGAIN. There is no mention of any HOA anywhere. There are no facilities to maintain. Everything here is county maintained. It's not the money, its the principal.