Problems with validation files Spring mvc 3

I'm having some problem with the Validation files in my Spring 3 project. I have a very basic validation project for tests thats the bean:

public class User {

@NotEmpty(message="no blank name")
@Size(min=2, max=20)
private String name="";

@NotEmpty(message="no blank email")
@Email
private String email="";

......getters and setters...... The function within the controller that accepts the request from the Form page and makes the necessary validation is:

    @RequestMapping(value="/displayUser",method=RequestMethod.POST)
public String displayUser(@Valid User user, Model model,BindingResult result){

    if(result.hasErrors()){
        return "form";
    }
    userList.add(user);

    model.addAttribute("user",user);

    return "redirect:displayUser";
}

But i dont think the code is the cause of the problem, as as soon as i start the server and run the project "which has always been working, since i test other spring things in there" i get the following Exceptions:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.validation.beanvalidation.LocalValidatorFactoryBean#0': Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1401) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:512) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:450) org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:290) org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:287) org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:189) org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:557) org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:842) org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:416) org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:443) org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:459) org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:340) org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:307) org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:127) javax.servlet.GenericServlet.init(GenericServlet.java:212) org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298) org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857) org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588) org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) java.lang.Thread.run(Thread.java:613)

Do you have any idea where thre problem could be? I'm trying t figure out but nothing, p.s i use Tomcat 6 and i have just downloaded the: "hibernate-validator-4.0.2.FINAL.jar" and validation-api-1.0.0.GA.jar