Servlet is currently unavailable FJ21

Galera, estou fazendo a apostila FJ21 da caelum, já terminei a parte de Spring MVC e Hibernate, e agora eu queria unir os dois frameworks.

Peguei os dois projetos que havia feito (um em cada framework) e resolvi aplicar o Hibernate aonde já estava com Spring.

Não fiz nada demais, apenas declarei as classe de modelo como @Entity e mais poucas coisas. Copiei todos os .jars do Hibernate para a pasta lib e importei pra o build path.

Porém, quando eu vou rodar a aplicação, da um erro informando que o Servlet esta indisponível (unavailable).

Segue meu web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
	id="WebApp_ID" version="2.5">
	<display-name>fj21-tarefas</display-name>
	<welcome-file-list>
		<welcome-file>index.html</welcome-file>
		<welcome-file>index.htm</welcome-file>
		<welcome-file>index.jsp</welcome-file>
		<welcome-file>default.html</welcome-file>
		<welcome-file>default.htm</welcome-file>
		<welcome-file>default.jsp</welcome-file>
	</welcome-file-list>

	<servlet>
		<servlet-name>Spring MVC Dispatcher Servlet</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<init-param>
			<param-name>contextConfigLocation</param-name>
			<param-value>
/WEB-INF/spring-context.xml
</param-value>
		</init-param>
		<load-on-startup>1</load-on-startup>
	</servlet>
	<servlet-mapping>
		<servlet-name>Spring MVC Dispatcher Servlet</servlet-name>
		<url-pattern>/</url-pattern>
	</servlet-mapping>
</web-app>

e o Spring Context

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xsi:schemaLocation="http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">

	<context:component-scan base-package="br.com.caelum.tarefas" />
	
	<mvc:annotation-driven />
	
	<mvc:resources mapping="/resources/**" location="/resources/" />

	<mvc:interceptors>
		<bean class="br.com.caelum.tarefas.interceptor.AutorizadorInterceptor" />
	</mvc:interceptors>

	<bean
		class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix" value="/WEB-INF/views/" />
		<property name="suffix" value=".jsp" />
	</bean>
</beans>

E o erro que o eclipse apresenta: 20/06/2012 11:18:03 org.apache.catalina.core.StandardWrapperValve invoke
INFO: Servlet Spring MVC Dispatcher Servlet is currently unavailable

Já busquei em um milhão de sites e achei várias pessoas com o mesmo problema, mas nenhuma com a respota.

Alguém poderia dar uma força?

Obrigado!

Posta o stacktrace completo.
Aliás, tem uns detalhes que acredito não estejam na apostila.
Quando unir Spring e Hibernate, faça com que o Spring gerencie o hibernate.
Pesquisa na internet a respeito dos dois. Tem muitos exemplo.s

Segue!

20/06/2012 13:23:21 org.apache.catalina.core.AprLifecycleListener init
INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:\Program Files\Java\jre6\bin;.;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;C:/Program Files/Java/jre6/bin/client;C:/Program Files/Java/jre6/bin;C:/Program Files/Java/jre6/lib/i386;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files\Enterprise Vault\EVClient\;C:\eclipse;
20/06/2012 13:23:21 org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:fj21-tarefas' did not find a matching property.
20/06/2012 13:23:21 org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:projetoDAO11' did not find a matching property.
20/06/2012 13:23:21 org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-bio-8080"]
20/06/2012 13:23:21 org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["ajp-bio-8009"]
20/06/2012 13:23:21 org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 536 ms
20/06/2012 13:23:21 org.apache.catalina.core.StandardService startInternal
INFO: Starting service Catalina
20/06/2012 13:23:21 org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.27
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/C:/Users/bpinto/Documents/Workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/fj21-tarefas/WEB-INF/lib/slf4j-log4j12-1.5.8.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/C:/Users/bpinto/Documents/Workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/fj21-tarefas/WEB-INF/lib/slf4j-log4j12-1.6.4.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
20/06/2012 13:23:22 org.apache.catalina.core.ApplicationContext log
INFO: Marking servlet Spring MVC Dispatcher Servlet as unavailable
20/06/2012 13:23:22 org.apache.catalina.core.StandardContext loadOnStartup
SEVERE: Servlet /fj21-tarefas threw load() exception
java.lang.NoSuchMethodError: org.slf4j.spi.LocationAwareLogger.log(Lorg/slf4j/Marker;Ljava/lang/String;ILjava/lang/String;[Ljava/lang/Object;Ljava/lang/Throwable;)V
	at org.apache.commons.logging.impl.SLF4JLocationAwareLog.debug(SLF4JLocationAwareLog.java:133)
	at org.springframework.core.env.AbstractEnvironment.<init>(AbstractEnvironment.java:100)
	at org.springframework.core.env.StandardEnvironment.<init>(StandardEnvironment.java:54)
	at org.springframework.web.context.support.StandardServletEnvironment.<init>(StandardServletEnvironment.java:43)
	at org.springframework.web.servlet.HttpServletBean.<init>(HttpServletBean.java:90)
	at org.springframework.web.servlet.FrameworkServlet.<init>(FrameworkServlet.java:211)
	at org.springframework.web.servlet.DispatcherServlet.<init>(DispatcherServlet.java:303)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
	at java.lang.reflect.Constructor.newInstance(Unknown Source)
	at java.lang.Class.newInstance0(Unknown Source)
	at java.lang.Class.newInstance(Unknown Source)
	at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:125)
	at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1136)
	at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1080)
	at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5015)
	at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5302)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1566)
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1556)
	at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
	at java.util.concurrent.FutureTask.run(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.lang.Thread.run(Unknown Source)
20/06/2012 13:23:22 org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-bio-8080"]
20/06/2012 13:23:22 org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["ajp-bio-8009"]
20/06/2012 13:23:22 org.apache.catalina.startup.Catalina start
INFO: Server startup in 1116 ms
20/06/2012 13:23:27 org.apache.catalina.core.StandardWrapperValve invoke
INFO: Servlet Spring MVC Dispatcher Servlet is currently unavailable

Valeu!

Tanto o Spring como o Hibernate usam o slf4j para log. Da uma olhada nos jars, vc pode ta com mais de uma versao dele ou a versao usada pelo spring nao e a mesma da versao usada pelo hibernate, e vice-versa.