I have the same issue and have called sky about this and their solution worked for about 30 mins. I have been with Sky for over 2 years. I am sure that the issue has got worse since sky glass was first advertised. Is this a ploy to get everyone to sign up for this.
Sky can not blame broadband as I am with them for that too. I need a definitive answer in 48 ours or I may have to consider moving to another provide for tv broadband and mobile as they are not fulfilling their contract with me.
I will also be seeking compensation for a service that I am not able to use.
would love to hear from Someone at sky very soon to get this matter resolved.