Windows 7: See Full Map Fails

Previously the Control Panel -> Network and Sharing Center -> 'See full map' function would correctly map my LAN. Recently I upgraded my wireless router, and now 'See full map' reports 'Windows cannot discover any computer or device'.

My previous setup:
* ActionTec M1000 acting as modem/router/DHCP server (IP 192.168.0.1)
* LinkSys WRT54G2 acting as access point (IP 192.168.0.2)
* Primary wired PC (IP via DCHP)
* Various wireless devices (IP via DHCP)

My current setup:
* ActionTec M1000 acting as modem in transparent bridge mode (no IP)
* D-Link DIR-601 acting as router/DHCP server (IP 192.168.0.1)
* Primary wired PC (IP via DCHP)
* Various wireless devices (IP via DHCP)



Internet connectivity and media sharing work properly among wired and wireless devices on the network. In Windows Explorer -> Network, I can see all the devices on the network (expect of course the modem).

Anyone have a clue why 'See full map' has stopped working?

OK here's one for the book of weird...

I was reading Ultimate Router Guide: Optimize Security & Performance and downloaded NetSurveyor to check Wi-Fi channel performance. I plugged in a Wi-Fi USB adapter on my primary PC, scanned channels, reconfigured the router to a clearer channel, and removed the adapter.

Now 'See full map' works fine. It correctly identifies all devices on the network.