NCO 3 RfcTypeConversionException: Cannot convert 00000901 into DATE

We have been using NCO 3 in an ASP.Net application to integrate with our 4.6B system without any issues.

We are now upgrading to ECC6 and the same programs we use for 4.6B (standard bapi calls ie BAPI_SALESORDER_GETLIST for example) are now producing an error.

Tried upgrading to latest version of NCO 3 (3.06) and still have the same problem.

The error is :

[RfcTypeConversionException: Cannot convert 00000901 into DATE (yyyyMMdd)]
SAP.Middleware.Connector.RfcScalarMetadataDate.ConvertString(String value, Object& currentValue) +295
SAP.Middleware.Connector.RfcDataContainer`1.SetValue(Int32 index, String value) +256

[RfcTypeConversionException: FIELD DOC_DATE of STRUCTURE BAPIORDERS (SETTER): cannot convert String into DATE]

I heard this was a bug in NCO 3 (Fixed in 3.02) but i am still experiencingthe same problem. I am not providing any dates in the call, but there is a problem getting date data back from the RFCTable

My code that works against 4.6B but fails on ECC6

Dim destination As RfcDestination = RfcDestinationManager.GetDestination(ABAP_APP_SERVER)

Dim func As IRfcFunction = destination.Repository.CreateFunction("BAPI_SALESORDER_GETLIST")

func.SetValue("Customer_Number", Request("Account").ToString)

func.SetValue("Sales_Organization", Request("SalesOrg").ToString)

func.Invoke(destination) << FAILS HERE

can anyone shed some light on why this would be failing against ECC6 ? I have made sure the date settings are the same for the user in both systems.