When I turn the MAC address validation off the iPhone connects just fine. So I tried to "import" the MAC address once it had connected, but same result.
maknz: Settings > General > About
Scroll down to Wi-Fi address.
Put that in your router. Done.
If it doesn't work, see freitasm's explanation.
Generally known online as OpenMedia, now working for Red Hat APAC a Technology Evangelist and Product Manager. Still playing with MythTV and digital media on the side.