Thanks Martin, those ports are open as per your cli info, but to be honest I think Ill give up on this now. I seriously dont know what to try next. Oh well. Your help was much appreciated. Chris.
Easiest way to troubleshoot any connectivity issue is to eliminate/disable as many factors as possible, then when you've solved the problem enable them one by one until the problem reappears.
In this case, shut down any firewall and other possible security related software-mechanics, ie. disable Vista's User Access Control (UAC) and make sure you're running as an administrator.