Error 1004 in Access VBA - excel

Question

I have spent a few hours researching this Error 1004 problem here, but did not find a similar situation.
In an access module I have 3 global objects (global in the module only) as follows:
Private objXLapp As Excel.Application
Private objXLworkbook As Excel.Workbook
Private objXLworksheet As Excel.Worksheet
All are instantiated correctly.
I am transferring data from a table into a spreadsheet through a function that is repeatedly called from within the module. The bare bones of the routines are below.
Private Function CreateLevel2(ByRef rstCASHFLOW As DAO.Recordset, ByRef currentRow As Long, colRef As String) As Boolean
Const PROC_NAME = "CreateLevel2"
On Local Error GoTo CatchAllErrors
Do
Retry:
objXLworksheet.Range("C" & currentRow - 1).Formula = rstCASHFLOW!PMTlevel2Code
... other code here
rstCASHFLOW.MoveNext
Loop Until rstCASHFLOW.EOF
Exit_Func:
On Local Error GoTo 0
Exit Function
CatchAllErrors:
If Err.Number = 1004 then
MsgBox "Press ok to continue"
Goto Retry
End If
Set ErrorMessage.OrgError = err
NewMsgBox eemUnknownError, MODULE_NAME, PROC_NAME
Err.Clear
Goto Exit_Func
End Function
Private Function CreateLevel1() As Boolean
Const PROC_NAME = "CreateLevel1"
On Local Error GoTo CatchAllErrors
objXLworksheet.Range("B" & currentRow - 2).Formula = rstCASHFLOW!PMTlevel1Code
… other code here
Exit_Func:
On Local Error GoTo 0
Exit Function
CatchAllErrors:
Set ErrorMessage.OrgError = Err
NewMsgBox eemUnknownError, MODULE_NAME, PROC_NAME
Err.Clear
GoTo Exit_Func
End Function
If I remove the "On Error" the program stops at the line of code assigning a value to the worksheet in the Function "CreateLevel2". If I exam all variables, none have lost scope and are valid. If I then tell the program to resume, it continues with no problem and the correct data is transferred to the spreadsheet.
If I include the "On Error" to catch the error and pop up a msgbox asking me to proceed (effectively suspending execution until I press ok), the code continues without any problems.
Is this just some querk of Access VBA?
When the error occurs, the variable currentRow is 13, the table variable rstCASHFLOW!PMTlevel2Code has a value (a string) and rstCASHFLOW.EOF is false. The XL objects are also ok. Checking through the Watch Window shows me that the object references are all fine.
Note there is only one objXLapp, one objXLworkbook and one objXLworksheet. The workbook only contains 1 worksheet.
I am totally stumped!
Can anyone help... thanks