Thanks for the responses.
I finally got it working (somehow), removed the Samsung viewer software and reset all the ActiveX stuff, cookies and anything else I could in IE, so working on VISTA and IE9.
Being totally new to CCTV, the networking has been by far the most difficult bit, I've learnt a lot about MAC and IP addresses, ActiveX, Router ports and firewalls!
Next challenge will be viewing via the Samsung.net server.
Thanks again.