InvalidClass Exception in javax .crypto. spec.SecretKeySpec

[Ramachandran Vaidyanathan]

Hi Friends,
Iam getting the following invalidclassexception while connecting from tomcat4.1 to websphere 3.5.6
java.io.InvalidClassException: javax.crypto.spec.SecretKeySpec; local class incompatible: stream classdesc serialVersionUID = 4363931942414077710, local class serialVersionUID = 6577238317307289933
at java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:459)
at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:152
1)
at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1435)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1
626)
Can somebody help me ASAP.....
TIA.
cheers