seems a bit lame i agree :(

i did write if you are not using the 5Ghz [SIZE=2]contact tp link support im sure they will help.[/SIZE]

sorry if i cant help contact tp link support direct you may get better help here >>> email http://goo.gl/yTQKe OR telephone http://goo.gl/WTZrB

some security types of encryption do not work on some devices so if you tried it without security just to see if it may be a issue its worth a try most people i work with and friends use WPA2-PSK AES...

have you tried turning off wireless security and reboot devices/router?

check this setting AP ISOLATION ?