Cómo reparar el byte 1 no válido de la secuencia UTF-8 de 1 byte

Estoy tratando de obtener el siguiente xml de db usando un método java pero recibo un error

Código utilizado para analizar el xml

DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();

InputSource is = new InputSource(new ByteArrayInputStream(cond.getBytes()));

Document doc = db.parse(is);

Element elem = doc.getDocumentElement();

// here we expect a series of <data><name>N</name><value>V</value></data>
NodeList nodes = elem.getElementsByTagName("data");

TableID jobId = new TableID(_processInstanceId);
Job myJob = Job.queryByID(_clientContext, jobId, true);

if (nodes.getLength() == 0) {
    log(Level.DEBUG, "No data found on condition XML");

}

for (int i = 0; i < nodes.getLength(); i++) {
    // loop through the <data> in the XML

    Element dataTags = (Element) nodes.item(i);
    String name = getChildTagValue(dataTags, "name");
    String value = getChildTagValue(dataTags, "value");

    log(Level.INFO, "UserData/Value=" + name + "/" + value);

    myJob.setBulkUserData(name, value);
}

myJob.save();

Los datos

<ContactDetails>307896043</ContactDetails>
<ContactName>307896043</ContactName>
<Preferred_Completion_Date>
</Preferred_Completion_Date>
<service_address>A-End Address: 1ST HELIERST HELIERJT2 3XP832THE CABLES 1 POONHA LANEST HELIER JE JT2 3XP</service_address>
<ServiceOrderId>315473043</ServiceOrderId>
<ServiceOrderTypeId>50</ServiceOrderTypeId>
<CustDesiredDate>2013-03-20T18:12:04</CustDesiredDate>
<OrderId>307896043</OrderId>
<CreateWho>csmuser</CreateWho>
<AccountInternalId>20100333</AccountInternalId>
<ServiceInternalId>20766093</ServiceInternalId>
<ServiceInternalIdResets>0</ServiceInternalIdResets>
<Primary_Offer_Name  action='del'>MyMobile Blue &#163;44.99 [12 month term]</Primary_Offer_Name>
<Disc_Reason  action='del'>8</Disc_Reason>
<Sup_Offer  action='del'>80000257</Sup_Offer>
<Service_Type  action='del'>A-01-00</Service_Type>
<Priority  action='del'>4</Priority>
<Account_Number  action='del'>0</Account_Number>
<Offer  action='del'>80000257</Offer>
<msisdn  action='del'>447797142520</msisdn>
<imsi  action='del'>234503184</imsi>
<sim  action='del'>5535</sim>
<ocb9_ARM  action='del'>false</ocb9_ARM>
<port_in_required  action='del'>
</port_in_required>
<ocb9_mob  action='del'>none</ocb9_mob>
<ocb9_mob_BB  action='del'>
</ocb9_mob_BB>
<ocb9_LandLine  action='del'>
</ocb9_LandLine>
<ocb9_LandLine_BB  action='del'>
</ocb9_LandLine_BB>
<Contact_2>
</Contact_2>
<Acc_middle_name>
</Acc_middle_name>
<MarketCode>7</MarketCode>
<Acc_last_name>Port_OUT</Acc_last_name>
<Contact_1>
</Contact_1>
<Acc_first_name>.</Acc_first_name>
<EmaiId>
</EmaiId>

El error

 org.apache.xerces.impl.io.MalformedByteSequenceException: Invalid byte 1 of 1-byte UTF-8 sequence.

Leí en algunos hilos que se debe a algunos caracteres especiales en el xml. Cómo arreglar este problema ?