Any Microsoft Virtual PC experts here?

I have been using Microsoft Virtual PC to run a virtual instance of XP on my
Windows XP laptop.

When I'm connected to my wireless 802.11 network at home, if I have the
virtual network adapter specified as 'Dell Wireless 1490 Dual Band
Mini-Card', from the Virtual PC I have no problems using the web browser to
connect to the internet.

However, when I'm not at home I use my AT&T Sierra Wireless 3G USB broadband
adapter.

If I change the Virtual PC to use the adapter 'Shared Networking (NAT)'
(Network Address Translation), I would expect to be able to browse to the
internet, but it fails.

When using Shared Networking (NAT), the network adapter shows the following
properties:

Physical Address 00-03-FF-9B-B6-F0
IP Address 192.168.131.66
Subnet Mask 255.255.255.0
Default Gateway 192.168.131.254
DHCP Server 192.168.131.254
Lease obtained 1/7/2009 11:21:26 AM
Lease Expires 1/12/2026 6:09:57 AM
DNS Servers 192.168.0.1
192.168.0.2

I assume that the Gateway address (192.168.131.254) is the internal
software-based router that Virtual PC is using...

As an experiment, I used ipconfig /all to view the DNS servers in the host
(physical) PC, and then I went into the Virtual PC network adapter and
manually configured the DNS servers to match those found on the physical PC.
After making this configuration change, I'm able to browse from the Virtual
PC while using my 3G adapter.

Question:
Is this working as designed? I don't like the idea of having to manually
edit the TCP/IP configuration within my Virtual PC every time I switch from
802.11 to 3G...

- sjl