Client Internal Error in SOAP response

Hi experts,

in PI 7.0 in a SOAP synchronous receiver channel, protocol HTTPS with certificate , I get this error:

<?xml version="1.0"?>

<env:Envelope xmlns:env="http://schemas.xmlsoap.org/soap/envelope/">

<env:Body>

<env:Fault>

<faultcode>env:Client</faultcode>

<faultstring>Internal Error</faultstring>

</env:Fault>

</env:Body>

</env:Envelope>

If I cut and paste the PI message in SOAP UI it works perfectly and web service give the correct response.

I've checked DO NOT USE Soap Envelop because Envelop is created by me with XSLT mapping.

In CC I'm using SOAP Action that I retrieved from "Action" in SOAP UI.

In module I have Transform text/xml;charset=utf-8

and

soap XMBWS.NoSOAPIgnoreStatusCode true

What could be the problem?

Thanks

Fabio