Recordset.update With SQL Native Client Doesn't Work

We recently migrated from SQL Server 7 to SQL Server 2005. Now there's a curious thing with some legacy applications. I have pasted some code below. Don't judge me, because like I said, it's legacy.

You can see, that I have two connection strings. One is commented and accessing via SQL Native Client. The other one is doing this through the old SQL Server driver. Funnily enough, when I use the new Native Client driver, the exception "Run-time error '-2147467259 (80004005)' [Microsoft][SQL Native Client]Invalid attribute value" is thrown in the rsPorder2.Update line. With the old driver, this works just alright.

Is this a bug? Is there a way, to make the code run, because we don't want to search the whole application for other occurances, if not necessary.

Any insights would be greatly appreciated.

Best regards,
DD

Dim ilinx As New ADODB.Connection
Dim rsPorder As New ADODB.Recordset
Dim rsPorder2 As New ADODB.Recordset
Dim cmdLinx As New ADODB.Command
Dim strConn As String

Dim lvIli_number As String

'strConn = "DRIVER=SQL Native Client;Server=10.0.14.7;Description=Test2k;UID=sa;PWD=asdf;APP=Microsoft® Access;WSID=DEHHC023;DATABASE=Linx;Network=DBMSSOCN;"

strConn = "DRIVER=SQL Server;Server=10.0.14.7;Description=Test2k;UID=sa;PWD=asdf;APP=Microsoft® Access;WSID=DEHHC023;DATABASE=Linx;Network=DBMSSOCN;"
ilinx.Open strConn
Set cmdLinx.ActiveConnection = ilinx

lvIli_number = "12345"
cmdLinx.CommandText = "SELECT * FROM porder WHERE previous_ili_no = '" & lvIli_number & "' "
cmdLinx.CommandType = 1

rsPorder.Open cmdLinx, , 1, 1

If rsPorder.EOF Then

cmdLinx.CommandText = "SELECT * FROM porder WHERE ili_no = '" & lvIli_number & "' "
cmdLinx.CommandType = 1
rsPorder2.Open cmdLinx, , 1, 3

If rsPorder2.RecordCount > 0 Then

rsPorder2("Locked") = 0
rsPorder2.Update
End If

End If
rsPorder.Close