Q:

The "Network Map" function in Windows 7 does not work for me. Why?

When I attempt to use the See Full Map function in Windows 7 Control Panel\Network and Internet\Network and Sharing Center it always abends. 
I really have no idea what the problem may be. I am sure this Windows network topology map function worked when I was using the Win 7 pre-release. However, now that I am using the retail RTM version of Windows 7 Home Premium (64-bit) I can no longer create a Network Map. My best guess from the (so-called) "help" provided is that a "device" (my router?) is incompatible with Microsoft's Link Layer Topology Discovery (LLTD) protocol. 
Below is a text diagram of my LAN. The error occurs even when the only system connected to the DIR-655 is my Win 7 desktop. This is why I suspect the DIR-655. But what could be wrong?? 
If a setting in my router is preventing LLTD from working I have no idea which it might be. Was hoping I might get a suggestion on what to start looking at.
                                Type of Connection
                                 [] coax
    ( Internet )                 | wired ethernet
      ( ISP )                    : wireless ethernet
         []
      [Motorola SB5100 "Surfboard" cable modem]
          |  WAN
     =====================================================
    + D-Link DIR-655 router, firmware v1.34NA, 2010/04/16 +
     =====================================================
       |    LAN             |                   :
       |                    |                 Wi-Fi
       |                    |                   :
    [Win 7 64-bit] [Seagate Dockstar] [MacBook OS X 10.6.4]

Update:
I've tried resetting the DIR-655 to factory defaults, rebooting Windows, then trying to map my network. It failed in the same way. But at least now I have some confidence the problem is not a result of anything (obvious) which I did to the configuration.
Update:
For what's it's worth, this function works again. I do no know when it started working again. I do not know why it is working. But it is working now. 
Is there a way to close a question as "No longer any point in pursuing?"

A:

Have you tried a firmware update? Latest firmware is 1.34NA, dated 5-20-2010
That model supports LLTD
http://www.microsoft.com/windowsxp/using/windowsvista/bowman_hardware.mspx
Also see this, problems with LLTD when using MAC filtering
http://www.dslreports.com/forum/r21605901-LLTD-on-a-DIR655-router

