Router does not support the Network Address Translator Type ?

[SBMongoos]

I have a DLink DIR-825. This is the Rev B1 running f/w 2.02NA. I tested it at this site moments ago:
http://www.microsoft.com/windows/using/tools/igd/default.mspx

I get a response of Not Supported for the 1) Network Address Translator Type and the 2) Traffic Congestion Test and the 3) TCP High Performance Test were "Not Run".

Can someone help me here as to why this occurred? It seems clear that since I'm running XP SP3 that 2 and 3 were not run as these tests are for Vista.

Here's the details I got for the NAT test:

Result:
Trying to resolve the Teredo server IP address
Primary Teredo server IP address: *.*.*.*
Secondary Terdeo server IP address: *.*.*.*
Starting exercise with primary Teredo server
Sending a Router Solicitation frame with ConeBit on
Waiting for Router Advertisement
Sending a Router Solicitation frame with ConeBit on
Waiting for Router Advertisement
Sending a Router Solicitation frame with ConeBit on
Waiting for Router Advertisement
Sending a Router Solicitation frame with ConeBit off
Waiting for Router Advertisement
Received a Router Advertisement frame
Starting exercise with secondary Teredo server
Sending a Router Solicitation frame with ConeBit off
Waiting for Router Advertisement frame
Received a Router Advertisement frame
The IGD's NAT type is SYMMETRIC

This router does have an IPv6 Connection Type option(s). Is it likely this came back Not Supported as the IPv6 is not setup? I'm with Comcast in the Denver area.

Perhaps this doesn't matter too much. Just surprised and wondering why I got the results I did and if there is anything I can do as I assume it would be a performance gain.

Thanks in advance.