TN4.6 database connection BizDocTypeStore Error

I have IS 4.6 with service pack 1 and TN 4.6 with Fix 4 running on a Solaris box. I am connecting with an external Oracle database. But, when I bring up the TN Console, I get the following error:

Error filling BizDocTypeStore cache
com.wm.data.BasicIDataCodable
java.lang.ClassCastException
java.lang.ClassCastException: com.wm.data.BasicIDataCodable
at com.wm.app.tn.db.BDTypeOperations.bytesToType(BDTypeOperations.java:197)
at com.wm.app.tn.db.BDTypeOperations.getAll(Compiled Code)
at com.wm.app.tn.db.BizDocTypeStore.fillCache(Compiled Code)
at wm.tn.doctype.init(Compiled Code)
at wm.tn.admin.startup(admin.java:523)

Can you point me to what I am missing?
Thanks very much for your help.