Couldn't generate CGLIB subclass of class

I am using Spring 2.0 with Hibernate 3.0 and JPA. I am also using annotations for JPA fields and Transactions. I am getting following error:
org.springframework.aop.framework.AopConfigExcepti on: Couldn't generate CGLIB subclass of class [class com.amazon.otb.legacy.manage.MetaManager]: Common causes of this problem include using a final class or a non-visible class; nested exception is java.lang.IllegalArgumentException: Superclass has no null constructors but no arguments were given
Caused by:
java.lang.IllegalArgumentException: Superclass has no null constructors but no arguments were given
at net.sf.cglib.proxy.Enhancer.emitConstructors(Enhan cer.java:718)
at net.sf.cglib.proxy.Enhancer.generateClass(Enhancer .java:499)
at net.sf.cglib.transform.TransformingClassGenerator. generateClass(TransformingClassGenerator.java:33)
at net.sf.cglib.core.DefaultGeneratorStrategy.generat e(DefaultGeneratorStrategy.java:25)
at net.sf.cglib.core.AbstractClassGenerator.create(Ab stractClassGenerator.java:216)
at net.sf.cglib.proxy.Enhancer.createHelper(Enhancer. java:377)
at net.sf.cglib.proxy.Enhancer.create(Enhancer.java:2 85)
at org.springframework.aop.framework.Cglib2AopProxy.g etProxy(Cglib2AopProxy.java:202)
at org.springframework.aop.framework.Cglib2AopProxy.g etProxy(Cglib2AopProxy.java:147)

It looks like Spring is trying to run my class MetaManager through CGLib even though I don't have any Transaction attributes defined for that class. Is there a way to disable CGLib for some beans. Thanks.

Here is my spring configuration file:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schem...-beans-2.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schem...ing-tx-2.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd"
default-autowire="byName" default-lazy-init="true" >

<bean id="entityManagerFactory"
class="org.springframework.orm.jpa.LocalContainerE ntityManagerFactoryBean">
<property name="jpaVendorAdapter">
<bean
class="org.springframework.orm.jpa.vendor.Hibernat eJpaVendorAdapter">
<property name="showSql" value="true" />
<property name="generateDdl" value="false" />
<property name="databasePlatform" value="org.hibernate.dialect.Oracle9Dialect" />
</bean>
</property>
<property name="loadTimeWeaver">
<bean class="org.springframework.instrument.classloading .ReflectiveLoadTimeWeaver"/>
</property>
</bean>


<bean id="txManager" class="org.springframework.jdbc.datasource.DataSou rceTransactionManager">
<property name="dataSource" ref="dataSource"/>
</bean>

<tx:annotation-driven transaction-manager="txManager"/>

<bean id="dataElementDao" class="com.amazon.otb.dao.hibernate.DataElementHib ernateDao"/>

<bean id="dataPointDao" class="com.amazon.otb.dao.hibernate.DataPointHiber nateDao"/>

<bean id="dataFrequencyDao" class="com.amazon.otb.dao.hibernate.DataFrequencyH ibernateDao"/>

<bean id="planningLevelDao" class="com.amazon.otb.dao.hibernate.PlanningLevelH ibernateDao"/>

<bean id="planningLevelManager" class="com.amazon.otb.service.impl.PlanningLevelMa nagerImpl">
<constructor-arg>
<ref bean="planningLevelDao"/>
</constructor-arg>
<property name="scenarioManager"><ref local="scenarioManager"/></property>
</bean>

......

Thanks.