java.lang.ClassCastException: com.interwoven.dc100

System

What does this (in servletd.log) mean when saving a DCR (the UI shows "Saving" but it never saves):

2004-06-03 10:20:29 - Ctx( /iw/webdesk ): Exception in: R( /iw/webdesk + /templating/DatacaptureServlet + null) - java.lang.ClassCastException: com.interwoven.dc100.core.TAndContainer
at com.interwoven.templating.DCRDocumentManipulator.setValues(DCRDocumentManipulator.java:80)
at com.interwoven.templating.DatacaptureServlet.doSaveDCR(DatacaptureServlet.java:1587)
at com.interwoven.templating.DatacaptureServlet.doGet(DatacaptureServlet.java:132)
at com.interwoven.templating.DatacaptureServlet.doPost(DatacaptureServlet.java:176)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
at com.interwoven.framework.base.FrameworkServlet.service(FrameworkServlet.java:66)
at com.interwoven.framework.auth.AuthServlet.service(AuthServlet.java:96)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:405)
at org.apache.tomcat.core.Handler.service(Handler.java:287)
at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372)
at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:797)
at org.apache.tomcat.core.ContextManager.service(ContextManager.java:743)
at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java:213)
at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:423)
at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:501)
at java.lang.Thread.run(Thread.java:484)