Index: ClassValidator.java
===================================================================
--- ClassValidator.java	(revision 15900)
+++ ClassValidator.java	(working copy)
@@ -26,9 +26,6 @@
 import org.hibernate.AssertionFailure;
 import org.hibernate.Hibernate;
 import org.hibernate.MappingException;
-import org.hibernate.mapping.PersistentClass;
-import org.hibernate.mapping.Property;
-import org.hibernate.mapping.Component;
 import org.hibernate.annotations.common.reflection.Filter;
 import org.hibernate.annotations.common.reflection.ReflectionManager;
 import org.hibernate.annotations.common.reflection.XClass;
@@ -36,6 +33,12 @@
 import org.hibernate.annotations.common.reflection.XMethod;
 import org.hibernate.annotations.common.reflection.XProperty;
 import org.hibernate.annotations.common.reflection.java.JavaReflectionManager;
+import org.hibernate.engine.SessionImplementor;
+import org.hibernate.mapping.Component;
+import org.hibernate.mapping.PersistentClass;
+import org.hibernate.mapping.Property;
+import org.hibernate.proxy.HibernateProxy;
+import org.hibernate.proxy.LazyInitializer;
 import org.hibernate.util.IdentitySet;
 import org.hibernate.validator.interpolator.DefaultMessageInterpolatorAggregator;
 import org.slf4j.Logger;
@@ -369,6 +372,20 @@
 			throw new IllegalArgumentException( "not an instance of: " + bean.getClass() );
 		}
 
+		// unproxy bean instance
+		if (bean instanceof HibernateProxy && Hibernate.isInitialized(bean)) {
+			LazyInitializer lazyInitializer = ((HibernateProxy) bean).getHibernateLazyInitializer();
+			SessionImplementor sessionImplementor = lazyInitializer.getSession();
+			// check if the given bean still has a session instance attached
+			if (sessionImplementor != null) {
+				// use the unproxy method of the persistenceContext class
+				bean = (T) sessionImplementor.getPersistenceContext().unproxy(bean);
+			} else {
+				// return the wrapped bean instance if there's no active session instance available
+				bean = (T) lazyInitializer.getImplementation();
+			}
+		}
+
 		List<InvalidValue> results = new ArrayList<InvalidValue>();
 
 		for ( int i = 0; i < beanValidators.size() ; i++ ) {
@@ -382,10 +399,13 @@
 			XMember getter = memberGetters.get( i );
 			if ( Hibernate.isPropertyInitialized( bean, getPropertyName( getter ) ) ) {
 				Object value = getMemberValue( bean, getter );
-				Validator validator = memberValidators.get( i );
-				if ( !validator.isValid( value ) ) {
-					String propertyName = getPropertyName( getter );
-					results.add( new InvalidValue( interpolate(validator), beanClass, propertyName, value, bean ) );
+				// make sure we only call validators for initialized bean properties
+				if (Hibernate.isInitialized( value ) ) {
+					Validator validator = memberValidators.get( i );
+					if ( !validator.isValid( value ) ) {
+						String propertyName = getPropertyName( getter );
+						results.add( new InvalidValue( interpolate(validator), beanClass, propertyName, value, bean ) );
+					}
 				}
 			}
 		}