Appendchunk/Update of varbinary column fails on ODBC Linked table?

I have a varbinary(max) column in a SQL Server table.  I am trying to
populate it through VBA code.
The code fails when the update to this column is done with a large
file and in a linked table environment in MS Access.
The linking is done using an ODBC system DSN.  It is interesting that
the code works fine with smaller files.

Const conChunkSize = 64000

Sub LoadJobOutputFileIntoDatabase(nJobPK&, strRe****tFile$)
    Dim Rcd As New ADODB.Recordset
    Dim strTempA$
    Dim nOffset&
    Dim strChunk As String
    Dim nLOBSize&

    strTempA = LoadFileIntoString(strRe****tFile)
    Rcd.Open "select * from brick_job where brick_job_pk=" & nJobPK,
CurrentProject.Connection, adOpenKeyset, adLockOptimistic
    nOffset = 0 ' Reset offset
    nLOBSize = LenB(strTempA)
    Do While nOffset < nLOBSize
        strChunk = LeftB(RightB(strTempA, nLOBSize - nOffset), _
            conChunkSize)
        Rcd!job_output.AppendChunk strChunk
        nOffset = nOffset + conChunkSize
    Loop
    Rcd.Update 'THIS STATEMENT GIVES RUN TIME ERROR
-2147217887(80040e21)
End Sub

However, the code works fine with ADO OLE Provider connection string.

Sub LoadJobOutputFileIntoDatabase(nJobPK&, strRe****tFile$)
    Dim Conn As New ADODB.Connection
    Dim Rcd As New ADODB.Recordset
    Dim strTempA$
    Dim nOffset&
    Dim strChunk As String
    Dim nLOBSize&

    Conn.Open "Provider=SQLOLEDB.1;User ID=user1;Password=pwd1;Initial
Catalog=Brickrpt;Data Source=butthead"
    strTempA = LoadFileIntoString(strRe****tFile)
    Rcd.Open "select * from brick_job where brick_job_pk=" & nJobPK,
Conn, adOpenKeyset, adLockOptimistic
    nOffset = 0 ' Reset offset
    nLOBSize = LenB(strTempA)
    Do While nOffset < nLOBSize
        strChunk = LeftB(RightB(strTempA, nLOBSize - nOffset), _
            conChunkSize)
        Rcd!job_output.AppendChunk strChunk
        nOffset = nOffset + conChunkSize
    Loop
    Rcd.Update
End Sub

Function LoadFileIntoString$(strFileName$)
    Dim nFile%, strTemp$, nFileLen&, strRec$, nCnt1&
    Const constBuffSize& = 2000000
    On Error GoTo LoadFileIntoString_Err
    LoadFileIntoString = ""
    nFile = FreeFile
    strRec = ""
    Open strFileName For Binary Access Read As #nFile
    nCnt1 = 0
    nFileLen = FileLen(strFileName)
    Do While True
        If EOF(nFile) Then
            Exit Do
        End If
        strTemp = Space(constBuffSize)
        Get #nFile, , strTemp
        If (nCnt1 + constBuffSize) > nFileLen Then
            strTemp = Mid(strTemp, 1, (nFileLen - nCnt1))
        End If
        strRec = strRec & strTemp
        nCnt1 = nCnt1 + Len(strTemp)
    Loop
    Close #nFile
    LoadFileIntoString = strRec
    Exit Function
LoadFileIntoString_Err:
    If nFile > 0 Then
        Close #nFile
    End If
    Exit Function
End Function

So, the question is, is there a limit on varbinary columns sup****ted
through ODBC?  If no then how I can fix the error.  I will appreciate
the help.

Ash