I just received an iPhone 3G from HK; the unlocked version. This is to replace my earlier 2G iPhone that was robbed sometime back.

It is working well, no issues here with the Celcom network. However there is this problem where the iphone appeared to have connected to my home wireless network as shown in by appropriate indicators, but it soon revert back to 3G or GPRS during operation. The same WiFi network is working fine on my PowerMac

It is also working fine in the WiFi network in my office. So this problem seems to be specific to my home WiFi which is supplied by a D-Link modem/WAN.

This appeared to have been documented in Apple's knowledge base (http://support.apple.com/kb/TS1398), and traced it to the MAC address filtering of the Modem. I have checked and found that the MAC filtering is not selected; so it should not be a problem.

I am still puzzled! Any ci-fu here can help??