Delphi 6 web service adjustment

Alredy have imported WSDL, but project was not able to detect parameters type:

// [WARNINGS]************************************************************** //
// Warning: Literal parameters of NewOrder() cannot be unwound
// Warning: Literal parameters of DataInventory() cannot be unwound
// Warning: Literal parameters of SearchInvoiceData() cannot be unwound
// Warning: Literal parameters of FindCocs() cannot be unwound
// Warning: Literal parameters of RegisterInventory() cannot be unwound
// Warning: Literal parameters of FindClient() cannot be unwound
// Warning: Literal parameters of VerifyOrder() cannot be unwound
// ************************************************************************ //

function NewOrder(const Credentials: NewOrder): string; stdcall;
function DataInventory(const parameters: DataInventory): string; stdcall;
function SearchInvoiceData(const parameters: SearchInvoiceData): string; stdcall;
function RegisterInventory(const parameters: RegisterInventory): string; stdcall;
function FindClient(const parameters: FindClient): string; stdcall;
function VerifyOrder(const parameters: VerifyOrder): string; stdcall;

Any one has a solution to complete this development using D6 ?