i was having the same problem, it turned out to be the setting on my computer. If ur using windows you need to get to - Wireless Network Connection Properties, then highlight IPV6/4, Click properties, then make sure 'Obtain an IP address automatically' and Obtain DNS server address automatically' are marked.
BUT BEFORE MAKING ANY CHANGES PLEASE WRITE DOWN THE DETAILS ON THOSE PAGES ICASE IT DOESNT WORK.