[Closed] Android - Odd WiFi problem

I recently stuck a new ROM on my Wildfire (CM7.2). All went smoothly, and everything works fine. When I enabled wifi, it connected to my home network without asking me to set it up, just connected automatically as though I had connected to it before. My network is WPA2 and hidden.

I guess my question is this - does Google back up the wifi settings somehow? I though a new ROM effectively made it a new phone? I wiped everything beforehand, all cache etc.

Any suggestions? Just a little concerned about security I guess.