I have the same problem with mine. Only happens with the router at my house. Any other router I can connect to with no problem, including the same model router I have at home.Re-flashing doesn't help.I've tried every possible router setting and still the same thing-connecting,connected,disconnected. And the signal strength goes from all the way up to all the way down.
There are several posts on the XDA forums from people having the same issue but with different model phones, no one has came up with an answer.
Gremlins.