I have some news:
Installed the 2.1.5-RELEASE, and test it clean (minimal config).
Associated with WIFI_SSID, but no ping or IP (since DHCP server is not available).
Set static IP address (20.0.0.100) and gateway (20.0.0.1) and tried ping. Ping to others common hosts (20.0.0.50, 20.0.0.150, 20.0.0.200, …) works fine. Ping to gateway fail, because the gateway does not respond ping from unknown hosts, so it's ok.
Now, the moment of truth!
With the same sets, I changed the MAC address, and so... nothing works anymore. :(
Tried others IPs and MACs address, but nothing.
Setting the MAC address to the real interface MAC address, the things come back to work.
I searched here about MAC spoof/clone, but didn't find nothing related.
Should this be a bug? May I report it? There is something else I can do to confirm "this bug"?
Cheers! o/