I solved this problem by trying lots of stuff, rapid fire.  I can't be absolutely sure what worked, but if you have the same trouble I had, I want to close this issue and offer some help for you.  Here's a few things I suggest:

• make sure you put the correct ALIAS for the new server in the installed DNN on your old server.  I was moving my DNN 4.0.3 from server1 to server2, so I first went into my DNN on server1 as ADMIN and added the ALIAS server2/dotnetnuke;
• I thought I could simply copy my server1/dotnetnuke installation over the new server2/dotnetnuke installation, but when I did that - I first got the problem of server2/dotnetnuke resolving to server1/dotnetnuke.  But then I got this idea: do a clean installation of DotNetNuke on server2, and make sure that is working - THEN copy the server1/dotnetnuke installation OVER the top of the server2/dotnetnuke application;

I did all this with at the console using folder/file cut and paste, not FTP, since I have admin access to this server.  After doing a copy of the contents of the /dotnetnuke application folder between server1 and server2 , I had to reset ACL's permissions on the server2/dotnetnuke applicaiton folder before the moved/migrated DNN installation on server2 would run without errors.  You probably know how to do this, but just incase you're new at this like me, here's what I mean by resetting ACL permissions:

(highlight your /dotnetnuke application folder, and right-click) > Sharing and Security... > Security [tab] >Advanced [button] > [x] Replace permission entries on all child objects with entries shown here that apply to child objects > Apply [button] > OK [button]

I find I must reset ACL permissions whenever I'm moving files into/out-of the /dotnetnuke application folder, or else I get errors when attempting to browse to the portal.

After getting the newly migrated/moved DNN to work on my new server2, I logged into DNN as ADMIN and removed the ALIAS for server1/dotnetnuke.

Then the DotNetNuke 4.0.3 Migration/Move between servers was successful, without the redirection problem I had in the previous post.

brak59: Thanks for adding to this thread.  You mention UserPortals table, so I'm wondering how much know-how you have about SQL and such (I'm super new to SQL/DNN, and I don't know much about the inner workings or either, yet).  Trouble I'm having is that I cannot upgrade this DNN 4.0.3 to 4.3.0 (this installation I moved) without losing my ability to Login to the portal.  [if you search this Subject: Upgrading from 4.0.3 -> 4.3.0 (Object reference not set to an instance of an object) you can read more about the trouble I'm having].

Do you know much about, say, doing a clean DNN installation, then importing into that clean install the tables (and data) from a previous installation?  I don't "get" :) how to do SQL exports/imports, etc.  I am trying to get familiar with SQL Server 2005 Management Studio Express; if I could use that to do table exports, imports - great!  But I could really use a few pointers about how to do it.