Maybe it's something related to this?
http://www.ispreview.co.uk/cgi-bin/n...FFVuEyeWZEzZxP
It might be down to all the national maint work VM are doing at present. Over the past couple of weeks speeds have been up and down when I'm back at home, especially games. Currently at work and the same sites places on our network here are fine.
Hope it improves.