我正在使用Oracle JDK 1.7（xjc 2.2.4-2）中的JAXB，并且在Unix版本的JDK上运行时有时会遇到此错误（不确定它在Windows上也不会发生）。知道它可能是什么吗？
java.lang.ClassCastException: [... my - class ... ] cannot be cast to com.sun.xml.internal.bind.v2.runtime.unmarshaller.DomLoader$State
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.DomLoader.startElement(DomLoader.java:104)
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.ProxyLoader.startElement(ProxyLoader.java:45)
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallingContext._startElement(UnmarshallingContext.java:486)
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallingContext.startElement(UnmarshallingContext.java:465)
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.InterningXmlVisitor.startElement(InterningXmlVisitor.java:60)
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.SAXConnector.startElement(SAXConnector.java:135)
at com.sun.xml.internal.bind.unmarshaller.DOMScanner.visit(DOMScanner.java:229)
at com.sun.xml.internal.bind.unmarshaller.DOMScanner.visit(DOMScanner.java:266)
at com.sun.xml.internal.bind.unmarshaller.DOMScanner.visit(DOMScanner.java:235)
at com.sun.xml.internal.bind.unmarshaller.DOMScanner.visit(DOMScanner.java:266)
at com.sun.xml.internal.bind.unmarshaller.DOMScanner.visit(DOMScanner.java:235)
at com.sun.xml.internal.bind.unmarshaller.DOMScanner.visit(DOMScanner.java:266)
at com.sun.xml.internal.bind.unmarshaller.DOMScanner.visit(DOMScanner.java:235)
at com.sun.xml.internal.bind.unmarshaller.DOMScanner.scan(DOMScanner.java:112)
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:309)
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal(UnmarshallerImpl.java:288)
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal(UnmarshallerImpl.java:238)