Installing a new SCCM site while another site is already in the domain

Hey All,
Before you all have a conniption, let me explain the scenario first.
Currently we have a QA segment that has a SCCM server that is working fine. However, the location will soon be closed and since the primary is on old hardware we decided to build a new server in a new location.
The server was built and SCCM installed. However, when I tried to install the MP and SLP roles, I found out there was another site on the same domain! So, everything was picking up the MP and SLP from that site. I can't even assign the new site server to it's own site!

I was able to discover the pcs that I want to migrate over to the new site, but cannot install the SCCM client to force them over.

When I checked the old QA server, I noticed the clientlocation.log file showed the IP address for the QA server instead of the server name. The other logs showed the same errors I am encountering in the new site, but somehow, they got the old site to work with the other site present.

So my question is how would I get the new site to work with that other site present. We can't shut it dwn, since it is managing over 100 servers (don't ask me why this is in a QA engineering environment if that is the case).

Thanks,

It's all about the boundaries. Each site should have its own boundaries that do not in any way overlap with the boundaries from the other site.

You will probably have to setup address ranges and not use ad site boundaries if your 2 configmgr sites are within the same AD site.

Arrgh!
THanks jsandys and fritschetom. I'll get someone to look at the boundaries on the other site and make sure nothing is overlapping.

OK.  Still looking into the overlapping.  However, shouldn't the MP at least not be erroring out?  I keep getting the following:
Call to HttpSendRequestSync failed for port 80 with status code 400, text: Bad Request
I ask because it was getting some HTTP 200 messages a few days ago before we uninstalled the MP and re-installed it.  Also, when I do the MP Test using MP Troubleshooter, the error is 500 Internal Server Error for the MPCert and MPList tests.
Additionally, I can't connect to Reporting from IE6 and yes, IE6 is what is on the server.
 
Thanks,