InfoPath Dev

I have posted twice already about these items seperately and have gotten them to work with limited success and am looking for some additional help because many of the solutions I have tried haven't worked.  I have an IP 2003 form that is pulling data from an SQL database.  The data structure shows the US_Customer_List_vw with the Customer Contacts and Customer Equip VW's as tables, as shown here:

• My Fields
• Query Fields (group)
• Data Fields (group)
• US_Customer_List_vw (group)
• Customer Name (Field)
• Account Number (Field)
• Address (Field)
• City (Field)
• US_Customer_ContactList_vw (group)
• First Name (Field)
• Last Name(Field)
• Phone Number (Field)
• US_Customer_Equipment_vw (group)
• Serial Number (Field)
• Customer (Field)
• Account (Field)
• EQ Name (Field)
• EQ Type (Field)
• My:Equipment_Summary
• • Serial Number (Field)
  • Customer (Field)
  • Account (Field)
  • EQ Name (Field)
  • EQ Type (Field)

I've built a query based on Account number that pulls back Customer information, Customer Contacts and Equipment list.  What I have been successfully able to do is build a drop down list in a repeating section where as you select an entry it is no longer available to select in subsequent repeating sections. 

Under the DDLB properties I:

1. Selected look up values in the forms data source
2. In Entries I selected my Serial number field from my data source 
3. Filtered my data so that it would not show duplicates
4.  /dfs:myFields/dfs:dataFields/d:SP_US_CUSTOMER_LIST_VW/d:SP_CUSTOMER_EQUIP_VW/@SERIALNO[not(. = ../../../../my:Equipment_Summary/my:SerialNumber)]

Tested it out and my data reports just fine.

The second part is populating the Text Box based on my Serial number selection.  I've written a rule under the serial number DDL properties where I have:

1. Selected set a fields value
2. Selected the field that I want populated Equipment Type in My: Equipment_Summary repeating section group
3. For the Value I set the formula to  EQ_Type[. = @SERIALNO]

Tested it out and it did not work for the first repeating section.  I've tried various other rules with again limited success.  What I want is when a Serial Number is selected that the Equipment Type is populated. 

I've read several strings about a secondary data source which I currently don't have set up I am just pulling the information from my data connection.  Do I need a secondary data source?  Will that affect my query results or the performance of the data query?  I think the syntax on my formula may be wrong but several of the options I have tried haven't worked either, how should the syntax work? 

 Sorry for the long drawn out question here.  

From looking at your site this seems to be something that can be done.  So I'm going to try to repost it in the General Section.