It gets all the way to connecting and then says disconnect
But are you hiding the SSID on the router? If so, try unhiding it. I've heard that there's something about hidden networks that the EVO doesn't like. You could also try updating the router's firmware or connecting to another WiFi network to see where the problem is.
MY evo connected fine when I first got the phone. Then we upgrade to Froyo and it won't connect anymore.
I have the same result. I used to connect fine, and now since the upgrade to froyo I can not get it to work. It shows that its connected to the wifi but I am unable to surf the web at all. It is like no data is being transfered at all.
@lognut - I have the same issue. If I turn WiFi on when I get home and surf the web, it connects and works well. I then turn the screen off and don't use the phone for awhile and then go back to it. Sometimes it will work and other times it will not. I have to turn WiFi off and then turn it back on in order to surf even though it shows the phone is connected.