Error in initializing Process from xml

Hi,
i'm running rapid miner 5.0 in a webapp, and i would like to read a rapid miner process from a xml file.

package tlicaring.analisys;

import java.io.File;
import java.io.IOException;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import tlicaring.service.NuovaAnalisi;

import com.rapidminer.RapidMiner;
import com.rapidminer.example.Example;
import com.rapidminer.example.ExampleSet;
import com.rapidminer.operator.IOContainer;
import com.rapidminer.operator.Operator;
import com.rapidminer.operator.OperatorException;
import com.rapidminer.tools.LogService;
import com.rapidminer.tools.XMLException;
import com.rapidminer.Process;

public class RapidMinerAnalisys {
	RapidMiner.ExecutionMode APPSERVER;

	protected final Log logger = LogFactory.getLog(getClass());

	public Set<Example> run(NuovaAnalisi n) {

		String file = "E:/Spring/tlicaring/war/WEB-INF/classifier.xml";	

		System.setProperty("rapidminer.init.weka","true");
		//System.setProperty("rapidminer.init.plugins","false");
		System.setProperty("rapidminer.init.jdbc.lib","true");
		System.setProperty("rapidminer.init.jdbc.lib.location","C:/Programmi/Rapid-I/RapidMiner5/lib/jdbc");
		System.setProperty("rapidminer.init.jdbc.classpath","false");	
		//System.setProperty("rapidminer.init.operators","C:/Programmi/Rapid-I/RapidMiner5/resources/com/rapidminer/resources/OperatorsCore.xml");
		System.setProperty("rapidminer.home","C:/Programmi/Rapid-I/RapidMiner5");

		RapidMiner.setExecutionMode(APPSERVER);

		Set<Example> results = new HashSet<Example>();

		File xml = new File(file);

		try {
			LogService.getGlobal().setVerbosityLevel(LogService.MAXIMUM);
			Process process = new Process(xml);

			IOContainer container = process.run();
			ExampleSet exampleSet = container.get(ExampleSet.class);

			Iterator<Example> iteratorExample = exampleSet.iterator();			

			while (iteratorExample.hasNext()) {
				Example example = iteratorExample.next();

				results.add(example);
			}

		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (XMLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (OperatorException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return results;
	}
}

but when i try to run my application i recive back these errors:

16-lug-2010 12.33.03 org.apache.catalina.startup.Catalina start
INFO: Server startup in 5614 ms

16-lug-2010 12.33.07 tlicaring.web.HomeController handleRequest
INFO: Returning home view with Fri Jul 16 12:33:07 CEST 2010

com.rapidminer.tools.XMLException: Unknown operator class: 'process'!
	at com.rapidminer.io.process.XMLImporter.parseOperator(XMLImporter.java:429)
	at com.rapidminer.io.process.XMLImporter.parseOperator(XMLImporter.java:404)
	at com.rapidminer.io.process.XMLImporter.parse(XMLImporter.java:294)
	at com.rapidminer.io.process.XMLImporter.parse(XMLImporter.java:233)
	at com.rapidminer.Process.readProcess(Process.java:1001)
	at com.rapidminer.Process.<init>(Process.java:219)
	at com.rapidminer.Process.<init>(Process.java:208)
	at tlicaring.analisys.RapidMinerAnalisys.run(RapidMinerAnalisys.java:60)16-lug-2010 12.33.11 tlicaring.web.NuovaAnalisiFormController onSubmit
	at tlicaring.web.NuovaAnalisiFormController.onSubmit(NuovaAnalisiFormController.java:26)
	at org.springframework.web.servlet.mvc.SimpleFormController.onSubmit(SimpleFormController.java:409)
	at org.springframework.web.servlet.mvc.SimpleFormController.onSubmit(SimpleFormController.java:381)
	at org.springframework.web.servlet.mvc.SimpleFormController.processFormSubmission(SimpleFormController.java:267)
	at org.springframework.web.servlet.mvc.AbstractFormController.handleRequestInternal(AbstractFormController.java:265)
	at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:153)
	at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:48)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:874)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:808)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:476)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:441)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
	at com.springsource.insight.collection.tcserver.request.HttpRequestOperationCollectionValve.invoke(HttpRequestOperationCollectionValve.java:60)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:379)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:619)

I think the problem is not the file access, but the linking between the xml Operators and the java Class.
In fact in the error stack there is: "com.rapidminer.tools.XMLException: Unknown operator class: 'process'!"

Is there someone that can help me?