UnsupportedClassVersionError on startup

Hi Bluemarsh,
I installed JSwat using the rpm: jswat-2.33-1jpp.noarch.rpm, I am using 
Fedora 3. I attempted to start JSwat using the instructions in 
README.html supplied with the rpm, as follows, and got an 
UnsupportedClassVersionError. Can you suggest what may be wrong?
June

 > java -Djava.ext.dirs=/usr/java/jdk1.5.0_03/lib -jar 
/usr/share/java/jswat.jar

Exception in thread "main" java.lang.UnsupportedClassVersionError: 
com/sun/jdi/Bootstrap (Unsupported major.minor version 49.0)
        at java.lang.ClassLoader.defineClass0(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:537)
        at 
java.security.SecureClassLoader.defineClass(SecureClassLoader.java:123)
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:251)
        at java.net.URLClassLoader.access$100(URLClassLoader.java:55)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:194)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:187)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:289)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:282)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:274)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:235)
        at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:302)
        at com.bluemarsh.jswat.Main.detectJPDA(Main.java:78)
        at com.bluemarsh.jswat.Main.main(Main.java:188)

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