I don't understand why you need any "port forwarding" done. I also have a dynamic IP, using a wireless router, vista laptop. I didn't have any connection issues apart from AVG interfering with Freelancer.
My issues were solved by reinstalling, and running absolutely everything "as admin". Alternatively, you can turn off User Access Control so it'll run as admin automatically.
Can you post exactly what the error message that pops up when you attempt to connect? Also, does it appear automatically or after a few seconds of "please waiting"?