PropertyPlaceholderConfigurer not working in Spring3

[umark]

Spring: 3.0.0M2
JDK: 1.6

We have had a custom instance of PropertyPlaceholderConfigurer working
since Spring 2.5.4 as follows. This does not seem to work with
Spring 3.0.0M2.

 package X;
 import org.springframework.beans.factory.config.PropertyPlaceholderConfigurer;
 public class MyConfigurer extends PropertyPlaceholderConfigurer {   
    //...
 }

Here is the usage of my property placeholder configurer:

// MyBeans.xml

 <bean id="propertyConfigurer"
		class="X.MyConfigurer"
		init-method="initializeBean"

		 p:searchSystemEnvironment="true"
		 p:systemPropertiesModeName="SYSTEM_PROPERTIES_MODE_FALLBACK"
	 />
	 
	<bean id="SomeBean"
		class="..."
		 p:property="${my.custom.property}"
	/>

MyConfigurer is never invoked; instead, it directly invokes
org.springframework.beans.factory.config.PropertyP laceholderConfigurer.processProperties,
which fails to evaluate ${my.custom.property}:

org.springframework.beans.factory.BeanDefinitionStoreException: Invalid bean definition with name 'my.custom.property' defined in class path resource [MyBeans.xml]: Could not resolve placeholder 'my.custom.property'
	at org.springframework.beans.factory.config.PropertyPlaceholderConfigurer.processProperties(PropertyPlaceholderConfigurer.java:269)
	at org.springframework.beans.factory.config.PropertyResourceConfigurer.postProcessBeanFactory(PropertyResourceConfigurer.java:75)
	at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:543)
	at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:518)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:358)
	at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:254)
  //...

Please help! Any suggestions appreciated!

/U

[umark]

Sorry to followup on my own post - the problem occurred because
another instance property placeholder configurer was being created
that was silently overriding the existing instance.

Is there a way to "boobytrap" instantiation of PropertyPlaceholderConfigurer
so as to abort the context instead of allowing it to continue with the
spurious instance of the placeholder configurer?

I mean, since the context will use only the latest instance of the
PropertyPlaceholderConfigurer, is there a way to query the
container and find the identity of the placeholder configurer
currently in use?

Regards

/U