Updated from SL to Mavericks - wifi killed

Hello everyone.

I upgraded from Snow Leopard to Mavericks. Wifi stopped working. Configuration shows no IP address for the router, nor DNS. I also have a MBP, and checked the config of both machines. That's the only difference.

Since before upgrade wifi worked perfectly, and since in the MBP upgrading from Lion to Mavericks also worked OK, I am annoyed and confused. I have tried everything I found around in the net: reseting PRAM, disabling wifi, deleting config files, deleting and recreating wifi connections, locations, setting IP's and DNS by hand, reseting the router... To no avail. It just seems the mac rejects to talk to the router to self configure, but since the hardware is the same as was before the upgrade, the only thing I see is Mavericks has something wrong...

Anyone has some idea? Thanks in advance