Erro na conversão de datas no VRaptor

Oi pessoal, estou tentando enviar um json que contem um campo data e está me retornando o seguinte erro:

com.thoughtworks.xstream.converters.ConversionException: Cannot parse date 1974-03-23 00:00:00.0

---- Debugging information ----
class : br.com.aberta.tzion.cadastroGlobal.entity.Aluno
required-type : java.util.Date
path : /data/niver
line number : -1

com.thoughtworks.xstream.converters.basic.DateConverter.fromString(DateConverter.java:97)

os codigos são o seguinte:

controller:
@Path("/aluno/alterar")
public void alterar(List registros) {
try{
Aluno a = (Aluno) this.alunoService.alterar(registros.get(0));
result.use(ExtJSJson.class).from(a).success(a != null).serialize();
} catch (Exception e) {
result.use(ExtJSJson.class).from(e.getMessage()).success(false).serialize();
}
}

ParametersProvider
@Component
public class JsonableParametersProvider implements ParametersProvider {
private ParametersProvider delegate;

   public JsonableParametersProvider(ParametersProvider delegate) {  
           this.delegate = delegate;  
   }  

   public Object[] getParametersFor(ResourceMethod method, List<Message> errors, ResourceBundle bundle) {  
          Object[] parameters = delegate.getParametersFor(method, errors, bundle);  
           for(int i = 0; i < parameters.length; i++) {  
                if((parameters[i] instanceof List<?>)&&
                	(!((List<?>)parameters[i]).isEmpty()) &&
                	(((List<?>)parameters[i]).get(0) instanceof List<?>) &&
                	((!((List<?>)((List<?>)parameters[i]).get(0)).isEmpty() &&
                	((List<?>)((List<?>)parameters[i]).get(0)).get(0) instanceof Jsonable)||
                	(((List<?>)((List<?>)parameters[i]).get(0)).isEmpty()))){
                	parameters[i] = ((List<?>)parameters[i]).get(0);
                 }  
           }  
           return parameters;  
    }  
}

Converter
@Convert(Jsonable.class)
public class JsonableConverter implements Converter<List> {
public List convert(String value, Class<? extends List> type, ResourceBundle arg2) {
ArrayList list = new ArrayList();

		   if (value.substring(0, 2).equals("[{")){
			   JSONArray arrayJson;
			   try {
				   arrayJson = new JSONArray(value);
				   for (int i = 0; i < arrayJson.length(); i++) {
					   String json = "{\"data\":"+ arrayJson.getJSONObject(i).toString() +"}";
					   addJsonable(list, json, type);
				   }
			   } catch (JSONException e) {
				   // TODO Auto-generated catch block
				   e.printStackTrace();
			   }
			   
		   }else if (!value.substring(0, 2).equals("[]")){
			   String json = "{\"data\":"+ value +"}";
			   addJsonable(list, json, type);
		   }
		   return list;
	}
	
	@SuppressWarnings("rawtypes") 
	private void addJsonable(List<Jsonable> list, String json, Class type){
		XStream xstream = new XStream(new JettisonMappedXmlDriver());
		xstream.alias("data", type);
		list.add((Jsonable) xstream.fromXML(json));
	}
}

Já tentei criar um converte pra Date, mas nem entra no converter

Converter Data:
    @Convert(Date.class)  
    public class DateConverter implements Converter<Date> {
    	public Date convert(String value, Class<? extends Date> type, ResourceBundle arg2) {
    		Date date = new Date();
    		try {
    			date = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").parse(value);
    		} catch (ParseException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    		return date;
    	}
    }

Valeu, desde já, Obrigado!!!