Both my iPhone 3GS's (Switched from Black to White) have had this problem so it is definitely my router. Whenever I leave the house and come back I have to go and select 'BT HomeHub QRNT' from the available WiFi list on my iPhone because it defaults back to BT Openzone. I don't have to re-enter the password but it is quite annoying. Also from time to time my iMac will drop off the internet and I have to turn the router off/on for it to connect again. Very bizarre!
Thanks
Thanks
