can't use Cactus with Java 5.0

HI,

I have trouble with my Cactus setup, I'm trying to have EJB tests on
Weblogic server using Cactus.
I downloaded the latest Cactus distribution(1.7.2), and used ANT 1.6.5 and
JRokcet 1.5.0_06 to drive my ANT-integrated tests.
Even I did not configure any <containerset> elements, that means run tests
locally, I still got the following exception:

java.lang.ClassFormatError:
org.apache.cactus.internal.configuration.ConfigurationInitializer
    at java.lang.ClassLoader.defineClass(Ljava.lang.String;[
BIILjava.security.ProtectionDomain;)Ljava.lang.Class;(Unknown Source)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java
:124)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:56)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
    at java.lang.ClassLoader.loadClass(Ljava.lang.String;Z)Ljava.lang.Class;(Unknown
Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268)
    at java.lang.ClassLoader.loadClass(Ljava.lang.String;)Ljava.lang.Class;(Unknown
Source)
    at java.lang.ClassLoader.loadClassFromNative(Ljava.lang.String;)Ljava.lang.Class;(Unknown
Source)
    at org.apache.cactus.internal.AbstractCactusTestCase.&lt;clinit&gt;(
AbstractCactusTestCase.java:53)
    at java.lang.Class.forName(Ljava.lang.String;ZLjava.lang.ClassLoader;)Ljava.lang.Class;(Unknown
Source)
    at java.lang.Class.forName(Ljava.lang.String;I)Ljava.lang.Class;(Unknown
Source)


Does Cactus have any restriction on JRE? JRE 5.0 not supported?
-- 
anfernee