Issue might have resolved itself strangely.
Was doing some testing tonight. Had a TZO domain set up because the windows live is still not working. Got someone to test my server and I can access my websever externally, FTP server, and RDP. However, remote access (WHS login, remote access computers and files) won't work.
I just now tried the windows live domain for about the 30th time and it worked! Now, remote access is completing its validation, saying that it is now available and now, remote access pages work. Very strange. Is there some compatibility issue with TZO DDNS that doesn't exist with Windows live? I have never used TZO before only windows live so have never seen such an issue.
Anyway - seems to all be working now. I have had a look around and haven't yet found anything saying that TZO won't work with remote access, so unsure what the issue was.
Thanks for allowing me to waste anyone's time who read this