spring 框架 在Tomcat5.0正常 升级到Tomcat 5.5 出现不能配置Spring 数据源问题

Tomcat5.0 + Spring2.x 这个结构已经使用了 1年多非常稳定。
但是在Tomcat5.5下却不能运行。
dataAccess.bean.xml 配置(节选)：-----------------------------------------------------

<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>classpath:/config/init.properties </value>
</list>
</property>
</bean>
<!-- DataSource Definition -->
<bean id="dataSource"
class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close">
<property name="driverClassName">
<value>${datasource.driverClassName} </value>
</property>
<property name="url">
<value>${datasource.url} </value>
</property>
<property name="username">
<value>${datasource.username} </value>
</property>
<property name="password">
<value>${datasource.password} </value>
</property>
<property name="maxActive">
<value>${datasource.maxActive} </value>
</property>
<property name="maxIdle">
<value>${datasource.maxIdle} </value>
</property>
</bean>

-----------------------------------------------------------------
init.properties文件内容(节选)：
hibernate.dialect=org.hibernate.dialect.SybaseDialect
datasource.driverClassName=com.sybase.jdbc3.jdbc.SybDriver
datasource.url=jdbc:sybase:Tds:192.168.0.1:7100/aa?charset=eucgb
datasource.username=aa
datasource.password=aa

#数据库连接池子大小
datasource.maxActive=50
datasource.maxIdle=5
datasource.maxWait=2400

===============================================================
问题:
1,在 Eclipse下选择正常
2,在 tomcat5.0下选择正常

3,在 tomcat5.5下错误：
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bea
n with name 'sessionFactory' defined in URL [jar:file:/D:/interfacework/apache-tomcat-
5.5.27/apache-tomcat-5.5.27/webapps/web98xx2/WEB-INF/lib/wfec_framework.jar!/config/da
taAccess.bean.xml]: Cannot resolve reference to bean 'dataSource' while setting bean p
roperty 'dataSource'; nested exception is org.springframework.beans.factory.BeanCreati
onException: Error creating bean with name 'dataSource' defined in URL [jar:file:/D:/i
nterfacework/apache-tomcat-5.5.27/apache-tomcat-5.5.27/webapps/web98xx2/WEB-INF/lib/wf
ec_framework.jar!/config/dataAccess.bean.xml]: Initialization of bean failed; nested e
xception is org.springframework.beans.TypeMismatchException: Failed to convert propert
y value of type [java.lang.String] to required type [int] for property 'maxActive'; ne
sted exception is java.lang.NumberFormatException: For input string: ""
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resol
veReference(BeanDefinitionValueResolver.java:275)

------------------------------------
我查google了一个上午始终没解决