windows mobile 5.0 device emulator (PPC or Smartphone) network connection through loopback adapter

I am developing http-network apps using vs 2005 and have been trying to get my compact framework app talk to a local http server running on the same disconnect laptop. I have installed the loopback adapter as well as the virtual machine driver stuff and using activesync for connecting and cradle. As a matter of fact, at one time I was able to successfully get the ppc app talk to the http server after many days of trying of different things. But then somehow I lost that setting and the connection is broken again.

At the moment, when the device app is sending the http request, the low level http stack throw the WebException (400 error) say that Bad request - invalid host name. It seems to me that the host name of the sender looks invalid to the receiver (http server). If I stop the local http server, and then if the device app send the same http request it gets an different error or timeout. So this seems to further confirm that the bad configuration of the host (IP) on the client side. I would really appreciate your help on this, at this point I am a little despirate after so many days of trying.

As far as I have tried, I have been messing with the following variables without real undstanding of all.

1. my pc network connections -> loopback adaptor connection -> properties

microsoft loopback adapter - configure -> network address

microsoft loopback adapter - Internet protocol(TCP/IP) ->properties

2. ppc emulator ->file->configure->network

3. vs.2005 ->tools->options->device tools->device->ppc phone -> emulator properties->network

4. vs2005->device emulator manager for connect to device and cradle device with active sync.

5. active sycn ->file->connection settings (tranport and connect to ...)

Thanks alot!

Kuo