Acrobat instance still running after closing using VBA

I have exhaustively searched for an answer, with limited success.

I open a document from Excel using:

Set AcroApp = CreateObject("AcroExch.App")
Set AvDoc = CreateObject("AcroExch.AVDoc")

'Open temporary file
AvDoc.Open "C:\Users\saylork\Documents\Waste Pickup Temp.pdf", ""
Set AcroForm = CreateObject("AFormAut.App")
Set Fields = AcroForm.Fields

After extracting data, I attempt to close it using:

Set Fields = Nothing
Set AcroForm = Nothing
AvDoc.Close True
AcroApp.CloseAllDocs
AcroApp.Exit
Set AcroApp = Nothing
Set AvDoc = Nothing

I've tried various ordering of the above just in case that made a difference, nope.

Also tried (APIs at top of code):

Sub CloseAdobeReader()
Dim strClassName As String
Dim hwnd As Long

strClassName = "AcrobatSDIWindow"
hwnd = FindWindow(strClassName, vbNullString)
If hwnd Then
SendMessage hwnd, WM_CLOSE, 0, ByVal 0&
Else
MsgBox "Adobe is not running!"
End If
End Sub

This will force a shut down. However, I'm opening and closing in a loop. It works the first time through (imports and closes), misses the second (no import, returns message) and works the third.

Is there a reliable way to close it?