We just upgraded to Spring 3.0.2 and junit 4.8.1 from Spring 2.5.6 and junit 4.4, and now see NoClassDefFoundError in those test classes which has the annotation @RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(...)

Googling around, I saw that there was a problem back with Spring 2.5.6 and junit 4.5+, but I haven't seen anyone else have the problem with Spring 3 and junit 4.5+.

My build environment is maven 2.2.1 and JRockit 1.6.0_05

All dependent jar is included in the build.
Hudson fingerprints:
aopalliance:aopalliance-1.0.jar
asm:asm-3.1.jar
cglib:cglib-2.2.jar
cglib:cglib-nodep-2.2.jar
com.ibm.websphere:mq-6.0.2.0.jar
com.sun:javaee-1.5.jar
commons-beanutils:commons-beanutils-1.8.0.jar
commons-collections:commons-collections-3.2.1.jar
commons-io:commons-io-1.4.jar
commons-lang:commons-lang-2.4.jar
commons-logging:commons-logging-1.1.1.jar
commons-pool:commons-pool-1.5.jar
joda-time:joda-time-1.6.jar
junit-addons:junit-addons-1.4.jar
junit:junit-4.8.1.jar
log4j:log4j-1.2.15.jar
org.dbunit:dbunit-2.4.7.jar
org.easymock:easymock-3.0.jardetails
org.easymock:easymockclassextension-3.0.jar
org.objenesis:objenesis-1.2.jar
org.slf4j:slf4j-api-1.5.6.jar
org.springframework:spring-aop-3.0.2.RELEASE.jar
org.springframework:spring-asm-3.0.2.RELEASE.jar
org.springframework:spring-beans-3.0.2.RELEASE.jar
org.springframework:spring-context-3.0.2.RELEASE.jar
org.springframework:spring-core-3.0.2.RELEASE.jar
org.springframework:spring-expression-3.0.2.RELEASE.jar
org.springframework:spring-jdbc-3.0.2.RELEASE.jar
org.springframework:spring-jms-3.0.2.RELEASE.jar
org.springframework:spring-orm-3.0.2.RELEASE.jar
org.springframework:spring-test-3.0.2.RELEASE.jar
org.springframework:spring-tx-3.0.2.RELEASE.jar
org.springframework:spring-web-3.0.2.RELEASE.jar
weblogic.server:ojdbc6-10.3.jar
xerces:xercesImpl-2.6.2.jar
xerces:xmlParserAPIs-2.6.2.jar
xmlunit:xmlunit-1.3.jar