Lithunwrap is free and is wonderful. I started out using uv mapper and had the same problem, I couldnt get him to answer my emails, so I went looking for an alternative.

I found lithunwrap and have been using it eversince thats been 5 or 6 years now I think.

Its great and never looked back, now, wether it works in Win 8 or not, I have no idea.