Duvida com o xstream

eu consigo fazer o xstream gerar um xml com 2 tipos de objetos diferentes de classes distintas do meu sistema, agora quero com o xtream gerar os objetos novamente deste xml que gerei, consigo fazer isso facilmente quando esse xml tem somente 1 objeto, porem quando o xml eh formado de mais de 1 objeto ele da erro.Alguem sabe me ajudar? o erro vai abaixo…

[Fatal Error] :281:2: The markup in the document following the root element must be well-formed.
Exception in thread “main” com.thoughtworks.xstream.io.StreamException: : The markup in the document following the root element must be well-formed.
at com.thoughtworks.xstream.io.xml.DomDriver.createReader(DomDriver.java:40)
at com.thoughtworks.xstream.XStream.fromXML(XStream.java:505)
at com.thoughtworks.xstream.XStream.fromXML(XStream.java:496)
at TesteCurvaXML.geraArray(TesteCurvaXML.java:117)
at TesteCurvaXML.main(TesteCurvaXML.java:68)
Caused by: org.xml.sax.SAXParseException: The markup in the document following the root element must be well-formed.
at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(Unknown Source)
at com.thoughtworks.xstream.io.xml.DomDriver.createReader(DomDriver.java:33)
… 4 more