Hi, 
   On my dev box and at my godaddy webhosting, I named my dnn folder "mydnn". My child portal is "tportal" for test portal.

  On my development box where the child portal DOES work, the mydnn is the root directory.
On dev, I reached mydnn with "http://localhost/mydnn". I created a virtual directory pointing to
mydnn. I reached tportal with "http://localhost/tportal".  (my alias was setup as localhost/tportal).

  On godaddy, the mydnn is a subdirectory.
  tportal has the portal-ID directory is under mydnn/Portals.
  I created 2 virtual directories under mydnn to test ....
1 - with set application root.
2 - without application root.
On my dev box, not quite sure what "set application root" on godaddy implies other than the creation of a folder under mydnn for set application root.
my aliases are ....
"www.domainname.com/tportal"
"domainname.com/tportal"
"www.domainname.com/mydnn/tportal" 

   this is my current setup. So, when I enter ...
"http://www.domainname.com/tportal" or
"http://www.domainname.com/mydnn/tportal" I get page not found.
  Just to make sure I am on the same page those who have a child portal working on godaddy ...
  1) On godaddy, should I be creating the virtual directory without the "set application root" ? 
  2) Is there anything in my web.config that plays into any of this ?
  3) Is there any DNS needed for child portals or is subhost.aspx suppose to do something ? Didnt seem
to need it in my dev environment.
  4) I tried to debug subhost.aspx in my dev environment and didnt reach any breakpoints there, so does
5.1.4 even use subhost.aspx ?
   Thanks for your time

  Jeff, 
     I see, when you create a virtual directory and select "set applicaiton root" you are specifying that this virtual directory is going to be an application, and, that it will be the root directory of that application. 
   
     As for creating a virtual directory on godaddy, I was wondering If I should create a virtual directory for either a Parent portal or a Child portal.  Because, in my dev environment It seemed like I needed to create a virtual directory  to get my child portal to work.  In my dev environment, the alias was "localhost/child" . When I created this virtual directory, I just pointed it to the dnn folder. 

    Yes, today I saw that a DNS entry is made to associate a domain name with a fixed IP address. So a DNS entry has nothing to do with a child portal. 
   
    Then I think I need to understand how my server see's the child portal "http://www.domain.com/child"   it permits it to be processed by dnn ? 
     When I enter "http://www.domain.com/dnn", I get my dnn site because the server knows that Default.aspx is one of the files to run. 
     But in the case of a child portal like "http://www.domain.com/child" , how is that seen, read and run in dnn ? 
     How could I debug it between the server and dnn to see if the problem is with how the server sees it, or if its how dnn sees it ?

      For a child portal, It seems that I should only be worried about the correct portal alias. I should not need to worry about the subhost.aspx ?