I have tried the passwords and the WPS button on the router several times. I just got my Blu Studio 6.0 about a day ago and it will only connect to my home wifi and no one else's.
I was having similar problems. At first we just rebooted the wireless router. Mine would connect but my daughters still would not connect. I read on the forums I should reboot the main router, take battery out, too. Anyway this worked and now all our blu's are working.