I recently bought iphone 4. I set the Wi-Fi link at residence with my orange router. WEP key entered, click again to Livebox and iphone picked up the link without problem. While the iphone is on, Wi-Fi is outstanding. The moment the phone goes in standby mode or is idle for a while, it drops the Wi-Fi signal. I get the message "Cannot join the network ". This is not usual. I have had many lengthy and frustrating calls to customer service apple. They all offer different advice and are very nice, but so far not anything work. If you have any solution then provides me please.