I am adding views to retrun json via MappingJacksonJsonView. I changed the resolver in the webmvc-config.xml to:

Code:
<bean class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver">
	  <property name="mediaTypes">
	    <map>
	      <entry key="html" value="text/html"/>
	      <entry key="json" value="application/json"/>
	    </map>
	  </property>
	  <property name="viewResolvers">
	    <list>
	      <bean class="org.springframework.js.ajax.AjaxUrlBasedViewResolver" id="tilesViewResolver">
			<property name="viewClass" value="org.springframework.web.servlet.view.tiles2.TilesView"/>
		  </bean>	      
	    </list>
	  </property>
	  <property name="defaultViews">
	    <list>
	      <bean class="org.springframework.web.servlet.view.json.MappingJacksonJsonView" />
	    </list>
	  </property>
	</bean>
This worked perfectly fine when running tomcat via "mvn tomcat:run" but failed from the tc server within STS 2.2.1 with the following error (truncated due to the size limitations).

Code:
Nov 15, 2009 4:07:35 PM org.aspectj.weaver.tools.Jdk14Trace error
SEVERE: org/codehaus/jackson/map/DeserializationConfig/class
org.aspectj.weaver.BCException: Null interface signature (element:0 of 1).  Type for which weare looking at interfaces is org.codehaus.jackson.map.MapperConfig.
when processing declare parents org.codehaus.jackson.map.DeserializationConfig
when processing type mungers 
when weaving 
when weaving type org.codehaus.jackson.map.ClassIntrospector
when weaving classes 

	at org.aspectj.weaver.bcel.BcelObjectType.getDeclaredInterfaces(BcelObjectType.java:251)
	at org.aspectj.weaver.ReferenceType.getDeclaredInterfaces(ReferenceType.java:594)
	at org.aspectj.weaver.ResolvedType.getDirectSupertypes(ResolvedType.java:66)
	at org.aspectj.weaver.patterns.TypePattern.matchesSubtypes(TypePattern.java:199)
	at org.aspectj.weaver.patterns.TypePattern.matchesSubtypes(TypePattern.java:181)
	at org.aspectj.weaver.patterns.ExactTypePattern.matchesSubtypes(ExactTypePattern.java:70)
	at org.aspectj.weaver.patterns.TypePattern.matchesStatically(TypePattern.java:127)
	at org.aspectj.weaver.patterns.DeclareParents.match(DeclareParents.java:62)
	at org.aspectj.weaver.patterns.DeclareParents.findMatchingNewParents(DeclareParents.java:347)
	at org.aspectj.weaver.bcel.BcelWeaver.applyDeclareParents(BcelWeaver.java:1711)
	at org.aspectj.weaver.bcel.BcelWeaver.weaveParentTypeMungers(BcelWeaver.java:1588)
	at org.aspectj.weaver.bcel.BcelWeaver.weaveParentsFor(BcelWeaver.java:1449)
	at org.aspectj.weaver.bcel.BcelWeaver.weave(BcelWeaver.java:1257)
	at org.aspectj.weaver.tools.WeavingAdaptor.getWovenBytes(WeavingAdaptor.java:423)
	at org.aspectj.weaver.tools.WeavingAdaptor.weaveClass(WeavingAdaptor.java:286)
	at org.aspectj.weaver.loadtime.Aj.preProcess(Aj.java:96)
	at org.aspectj.weaver.loadtime.ClassPreProcessorAgentAdapter.transform(ClassPreProcessorAgentAdapter.java:52)
	at com.springsource.tcserver.ltw.TomcatAspectJWeavingClassLoader$LoggingClassFileTransformer.transform(TomcatAspectJWeavingClassLoader.java:99)
	at org.springframework.instrument.classloading.WeavingTransformer.transformIfNecessary(WeavingTransformer.java:95)
	at org.springframework.instrument.classloading.WeavingTransformer.transformIfNecessary(WeavingTransformer.java:78)
	at org.springframework.instrument.classloading.tomcat.TomcatInstrumentableClassLoader.findResourceInternal(TomcatInstrumentableClassLoader.java:114)
	at org.apache.catalina.loader.WebappClassLoader.findResource(WebappClassLoader.java:958)
	at org.apache.catalina.loader.WebappClassLoader.getResource(WebappClassLoader.java:1093)
	at org.aspectj.apache.bcel.util.ClassLoaderRepository.toURL(ClassLoaderRepository.java:276)
	at org.aspectj.apache.bcel.util.ClassLoaderRepository.loadClass(ClassLoaderRepository.java:289)
	at org.aspectj.weaver.bcel.BcelWorld.lookupJavaClass(BcelWorld.java:390)
	at org.aspectj.weaver.bcel.BcelWorld.resolveDelegate(BcelWorld.java:373)
	at org.aspectj.weaver.ltw.LTWWorld.resolveDelegate(LTWWorld.java:107)
	at org.aspectj.weaver.World.resolveToReferenceType(World.java:397)
	at org.aspectj.weaver.World.resolve(World.java:282)
	at org.aspectj.weaver.World.resolve(World.java:195)
	at org.aspectj.weaver.bcel.BcelGenericSignatureToTypeXConverter.classTypeSignature2TypeX(BcelGenericSignatureToTypeXConverter.java:95)
	at org.aspectj.weaver.bcel.BcelGenericSignatureToTypeXConverter.fieldTypeSignature2TypeX(BcelGenericSignatureToTypeXConverter.java:111)
	at org.aspectj.weaver.bcel.BcelGenericSignatureToTypeXConverter.typeSignature2TypeX(BcelGenericSignatureToTypeXConverter.java:184)
	at org.aspectj.weaver.bcel.BcelGenericSignatureToTypeXConverter.typeSignature2TypeX(BcelGenericSignatureToTypeXConverter.java:173)
	at org.aspectj.weaver.bcel.BcelMethod.unpackGenericSignature(BcelMethod.java:552)
	at org.aspectj.weaver.bcel.BcelMethod.evictWeavingState(BcelMethod.java:572)
	at org.aspectj.weaver.bcel.BcelObjectType.evictWeavingState(BcelObjectType.java:864)
	at org.aspectj.weaver.bcel.BcelObjectType.weavingCompleted(BcelObjectType.java:879)
	at org.aspectj.weaver.bcel.BcelWeaver.weaveAndNotify(BcelWeaver.java:1533)
	at org.aspectj.weaver.bcel.BcelWeaver.weave(BcelWeaver.java:1322)
	at org.aspectj.weaver.tools.WeavingAdaptor.getWovenBytes(WeavingAdaptor.java:423)
	at ..... a lot more of the trace......
Thanks so much!