InfoPath Dev

Scenario: I have a drop down box with multiple entries. I have associated rules on the DDown box that pass different formulas to another field called TotalBox.  
  So if the user selects A from the DDown box. The formula is 1 + 1 and it displays 2 in the TotalBox read only field.

Problem: I added a new entry to the DDown box ( C ) that will display a new field (called QtyBox) and it includes an associated formula (3 + 3 )+ QtyBox. However, the formula does not calculate because it does not update from the QtyBox field. The ability to "Update Value when the Rest..." does not exist.

I've thrown together a simple example. C fails. Please see attached.  How can I get this to work?

Update: So as a pseudo workaround, I added another field called CTotal. I removed the formula from the DDown box for C and added the formula to the new box. It sort of works... What is occuring is that it is not associating the correct formula values from line item 12 on my sharepoint list. Instead, it appears to be pulling values from Line item 1.

Not sure how to associte with the correct row in SharePoint. Argh, solved one problem only to create another.  Any Ideas anyone? 

In your sample form, you also need to add a rule to QtyBox to update your TotalBox.

Rules run when the field with the rule changes. You set the drop down to C, and at that point QtyBox is blank. So, it has no value to include in your calc. But if you add another rule to the QtyBox field to set the TotalBox field, you'll be find.

As to your new issue - you'll need to filter your data to get the correct value - so, for example, if your drop down uses the SharePoint ID for the value, your formula to set the total needs to include a filter where SharePoint ID from the secondary data source = DropDownBox in the main data source.