In the last couple of months my win7 desktop PC has developed this problem. The firewall periodically blocks autherised programes & websites. I know is the firewall as when I turn firewall of everything works fine & I can access them on my ipad. I have found if I reset default firewall setting this fixes the problem for a couple of days. I have searched here for a solution but have found nothing thats reasonably new like within in the last 2 years. I have done virus, spyware & malware scans using Avast, Spybot & windows own security programes but no problems were found. Any suggestions are welcome.