Can't insert values into Editable text fields using VBA

I am brand new to Acrobat. If this is not the right community please let me know.

I have an Access 2010 application that has to fill in a fillable PDF form. I have Acrobat Pro 9.0 Extended. I've referenced the Acrobat Type library in my application. I am using VBA.

I am looping over an array which contains the PDF field names and the values to insert. I pulled the field names off the PDF using JSObject, so I know they're correct. The problem is that the values are not being inserted.

My code:

Dim acrobatApp As Acrobat.CAcroApp

Dim PDDoc As Acrobat.CAcroPDDoc

Dim jso As Object

    Set acrobatApp = CreateObject("AcroExch.App")

    Set PDDoc = CreateObject("AcroExch.PDDoc")

    PDDoc.Open(FilePath)

    Set jso = PDDoc.GetJSObject

    For n = 0 To numFields - 1

        jso.getfield(arFldNames(n)).Value = arValues(n) 'WHY ISN'T THIS INSERTING?

        Debug.Print "Set field " + arFldNames(n) + " = " + arValues(n)

        Debug.Print "jso.GetField(" & arFldNames(n) & ") " & " = " & jso.getfield(arFldNames(n)).Value

    Next n

Debug Output:

Set field us-ids[0].sfpatitemflow[0].patItemsf[0].patnumbertxt[0] = 123 '[123 is the value that should be inserted]

jso.GetField(us-ids[0].sfpatitemflow[0].patItemsf[0].patnumbertxt[0])  = '[null] is the value that was inserted. WHY?