pub.sap.idoc:encodeString service error

Hi,

I need to convert the IDOC to string.

I have SAP Listener and notification.

The document is published to Broker and in the subscribing service I have these service

pub.sap.idoc:documentToIDoc ( i/p : the doc subscribed )
pub.sap.idoc:encodeString ( i/p : idoclist from above service and server name)

now the service pub.sap.idoc:encodeString errors out with the below error message.
Error :

java.lang.IndexOutOfBoundsException: WmSAP Adapter: Index greater than number of IDoc fields.

What am I missing.

Any help is appreciated.

Thanks!
-Vkram

I saw a fix/patch SAP_7.1_Fix4 for the same issue in empower.havnet tried it yet.

If you guys have any other info it wud be great too.

Thanks!