Maybe you can try regenerating your ssl certifcate as per link below. not 100% this will work as im new to openvpnAs. but i just wanted to give you at least something to try. I have a few post that no one has responded to so i know how frustrating it is.
http://openvpn.net/index.php/access-server/docs/admin-guides/175-how-to-replace-the-access-server-private-key-and-certificate.html
http://openvpn.net/index.php/open-source/documentation/howto.html#pki