Your EhCacheManagerFactoryBean may be a singleton, but it's building multiple CacheManagers and trying to give them the same name. That violates Ehcache 2.5 semantics.
Versions of Ehcache before version 2.5 allowed any number of CacheManagers with the same name (same configuration resource) to exist in a JVM.
Ehcache 2.5 and higher does not allow multiple CacheManagers with the same name to exist in the same JVM. CacheManager() constructors creating non-Singleton CacheManagers can violate this rule
Tell the factory bean to created a shared instance of the CacheManager in the JVM by setting the shared property to true.
<bean id="cacheManager" class="org.springframework.cache.ehcache.EhCacheManagerFactoryBean" p:shared="true"/>