Frostwire crashes on 9.04

[mrwasabi]

Greetings,
I did a fresh install of Ubuntu 9.04 on my laptop, installed everything according to the perfect desktop tutorial, then installed frostwire and it crashes when I try to start it, here's the crash report:

FrostWire version 4.17
Java version 1.6.0_13 from Sun Microsystems Inc.
Linux v. 2.6.28-11-generic on i386
Free/total memory: 4468032/5177344

java.lang.NoClassDefFoundError: org/limewire/util/VersionUtils
at com.limegroup.gnutella.gui.GUILoader.load(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Nativ e Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Native MethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(De legatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.limegroup.gnutella.gui.Main.main(Unknown Source)
Caused by: java.lang.ClassNotFoundException: org.limewire.util.VersionUtils
at java.net.URLClassLoader$1.run(URLClassLoader.java: 200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.j ava:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:3 07)
at sun.misc.Launcher$AppClassLoader.loadClass(Launche r.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:2 52)
at java.lang.ClassLoader.loadClassInternal(ClassLoade r.java:320)
... 6 more

STARTUP ERROR!

Can you shed any light on why this is happening? TIA

Mr wasabi