The issue might be related to Domain Name System (DNS) settings. TPG might be using different DNS servers than Telstra, and those servers could be having trouble resolving vk.com. You can try changing your DNS settings to a public DNS provider like Google (8.8.8.8 and 8.8.4.4) or OpenDNS (208.67.222.222 and 208.67.220.220). Here's a guide to help you change DNS settings: slope 3 [Change DNS settings ON Google [invalid URL removed]] ... View more