If your IP was blacklisted from Facebook, that would be your *servers* IP address and not your own home IP address. Unfortunately, this can happen if you're in a shared hosting environment where many sites/servers are all sharing the same IP address. In that case, any one of those sites can do 'bad things' that makes Facebook block the whole IP address.
The only things I can recommend are:
1) Go to the
Facebook Developer Area
. Click into your app and go to Settings -> Advanced.
Make sure the "Server IP Whitelist" and "Update Settings IP Whitelist" are both blank. If they have an IP in there, it would explain why your server isn't allowed to talk to Facebook if it's IP isn't listed there.
2) Contact your hosting company and let them know that you need a different IP address. Explain what happened, and ensure them it wasn't you doing anything against Facebook's terms of service. Sometimes it's easy to get changed to a different IP address, sometimes it's difficult.
I hope that helps explain, but if you have any other questions, just let me know.
Thanks,
Alex