InfoPath Dev

I have created a requisition form in InfoPath 2003 (submissions go to SharePoint 2003, most users in WinXP environment) and my question is about setting up user roles. I have user roles set up in order to show a particular view based upon who the person is. Person #1 initiates the request and sees View #1. They submit and an email goes to Person #2. That person opens up the form and sees View #2 that allows them to add their approval, notes, date of approval and then there is a submit button for them. Person #1 can't see Person #2's entries. It all seems to be set in order but I'm getting the following error when they try to open the form:

Form template: https://mysharepointserver/sites/.../Requisitions/Forms/template.xsn
Your user name or group membership cannot be verified because your security settings do not permit it.

I have the user role set up to go by a SharePoint list. I don't think I will be able to get corporate to agree to creating an Active Directory group for each step in our process (from initiator, to approver, to manager for assigning resource, to resource). Everything else in the form seems to be working. Can you use a SharePoint list for User Roles? My SharePoint Users list has User Name, Role, Phone Number & Email. Thanks in advance for any assistance you may be able to provide.

This is not ideal but should work. It is nicer to admin in AD rather than a seperate list.

In your form setup a data connection to the list.

On load the whole list will load

Then use filters on the list to get the details where username = the username for the list.

Then you have the data for your logic.