WN1000RP - Nokia Lumina 920 Connection Issue

My WN1000RP is successfully extending my wireless network for 4 different devices (xbox, tablet, phone, PC). However, I am having an issue connecting my Windows Phone 8 Nokia Lumina 920 to the extender. All connection attempts time out. When I look at the 'Network Devices' page on the extender's configuration I see an entry for the phone's MAC, a virtual MAC, but no IP address - this is the only entry in the list with no IP address. When I look at my DHCP table on my router, I see an entry for the virtual MAC + a valid IP address. My router is a Motorola Surfboard SBG6580.

The 920 has no problems connecting to other wireless networks and is able to successfully connect directly to my wireless router. I can also connect the 920 to the extender when the extender is not associated with another wireless network (and so is not proxying DHCP traffic) - I can even run the complete initial configuration from the 920 using the mobile configuration pages of the extender.

I suspect there's something going wrong as the extended proxies the DHCP requests at connection time, but I don't have any traffic diagnostics to support that or any ability to modify how this handshake is performed.

Any assistance would be greatly appreciated, otherwise I'm going to have to send the device back to Amazon.

-- James