Similar problem here. I'm on a Droid Razr, v4.1.2... I haven't had any problems connecting to my home WiFi for almost 2 years.
Suddenly (last two weeks), the Droid simply REFUSES to connect to my home WiFi. It shows my home WiFi network as available, shows signal strength as Excellent; but when I select "Connect to Network," the Droid just displays "Connecting..." and a signal strength symbol that continuously flashes between full strength and no signal. But it never connects.
As soon as I switch to my backup network (which works fine), my home network drops down in the list and shows as available with excellent signal strength again. The Droid KNOWS it's there, but won't connect to it.
I've triple-checked my network password (it's correct), and my other wireless devices have no problem connecting to the home network. Just the Android Razr is acting up. WTH?
Thanks in advance, people!