Hey guys I hope someone can help me:

I downgrading from 1.1.1 on the iphone to 1.0.2 and since then my wifi has not been working. It can detect networks perfectly and their signal strengths and what not but when I try to join it always gives me a "can not connect to network" error. It doesn't even work in my own house. I used to have a 1.0.2 iphone and I could get wifi but I can't with this one. I downgraded using windows if that helps. The only time I can connect is when I'm right next to the router and even then it's shoddy.