After the upgrade, when it wiped the configuration did you reload a config file or did you manually reenter your settings? Try manually entering everything instead of using the configuration file (maybe its corrupt or has some bad settings)... take a screenshot of all your open ports, gaming settings, internet config before you do so.
What settings are you using for wireless, are you specifying a specific channel or allowing it to scan?
There's always the possibility that your environment is causing the errors?