140311 is the latest version indedd.

Did you follow this instruction? http://www.tp-link.com/en/article/?faqid=634

Wilson, there is an instruction which may help. http://www.tp-link.com/en/article/?faqid=341

Bypassing the router, can you access internet on your PC? Connecting to the router, if only your PC cannot access internet, what's the IP address, default gateway, DNS obtained? What's the status of...

I cannot open the link you provided. On router page, go to DHCP---DHCP settings, there is Address Lease Time. I'm not sure if it helps. Any friends using android phones? You'd better give a try.

You followed http://www.tp-link.com/en/article/?faqid=244? Can you ping the router at remote site as the instruction? Can you ping file server or computers at remote site?