Problems passing parameters from UWL to a SAP Transaction

Hello experts,

We use SAPTransactionLauncher to lanch a SAP Transaction from UWL, we need to pass parameters to this transacction.

The transaction MIR4 is launched perfect, but the parameters don't appear in the first screen.

This is the XML:

<Action name="launchSAPAction" handler="SAPTransactionLauncher">

   <Properties>

    <Property name="TransactionCode" value="MIR4"/> 

    <Property name="GuiType" value="WinGUI"/>

    <Property name="RBN" value="${item.NumDocumento}"/>   

    <Property name="GJR" value="${item.Ejercicio}"/>   

   </Properties>

</Action>     

Any idea?

Thanks.