既に作成済みの既存のテーブルに複数選択型を追加すると、アプリケーションエラーが発生します。
以下はエラー発生時のアプリケーションログ。

2006-08-03 10:54:18,859 ERROR [/tuigwaa] - Application Error Detected and Forwarded
org.hibernate.MappingException: Association references unmapped class: com.isenshi.tuigwaa.db.dynamic.test1.Tgw_m2m_tgw_entity
at org.hibernate.cfg.HbmBinder.bindCollectionSecondPass(HbmBinder.java:2344)
at org.hibernate.cfg.HbmBinder$CollectionSecondPass.secondPass(HbmBinder.java:2618)
at org.hibernate.cfg.CollectionSecondPass.doSecondPass(CollectionSecondPass.java:35)
at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1012)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1168)
at org.seasar.tuigwaa.database.DynaConfiguration.build(DynaConfiguration.java:215)
at org.seasar.tuigwaa.database.DynaConfiguration.resetConfiguration(DynaConfiguration.java:195)
at org.seasar.tuigwaa.database.DynaConfiguration.alterTable(DynaConfiguration.java:167)
at org.seasar.tuigwaa.database.DynaDatabaseServiceImpl.alterTable(DynaDatabaseServiceImpl.java:139)
at org.seasar.tuigwaa.database.DynaDatabaseServiceImpl$$EnhancedByS2AOP$$1c18a4c.alterTable$$invokeSuperMethod$$(DynaDatabaseServiceImpl$$EnhancedByS2AOP$$1c18a4c.java)
at org.seasar.tuigwaa.database.DynaDatabaseServiceImpl$$EnhancedByS2AOP$$1c18a4c$$MethodInvocation$$alterTable0.proceed(MethodInvocationClassGenerator.java)
at org.seasar.extension.tx.RequiredInterceptor.invoke(RequiredInterceptor.java:40)
at org.seasar.tuigwaa.database.DynaDatabaseServiceImpl$$EnhancedByS2AOP$$1c18a4c$$MethodInvocation$$alterTable0.proceed(MethodInvocationClassGenerator.java)
at org.seasar.tuigwaa.database.DynaDatabaseServiceImpl$$EnhancedByS2AOP$$1c18a4c.alterTable(DynaDatabaseServiceImpl$$EnhancedByS2AOP$$1c18a4c.java)
at org.seasar.tuigwaa.model.ModelServiceImpl.alterEntity(ModelServiceImpl.java:185)
at org.seasar.tuigwaa.controller.EntityAction.doSave(EntityAction.java:127)
at org.seasar.tuigwaa.util.ajax.AbstractRowSetAction.saveRowSet(AbstractRowSetAction.java:62)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.struts.actions.DispatchAction.dispatchMethod(DispatchAction.java:270)
at org.apache.struts.actions.DispatchAction.execute(DispatchAction.java:187)
at org.apache.struts.actions.MappingDispatchAction.execute(MappingDispatchAction.java:169)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
at org.seasar.struts.processor.S2TilesRequestProcessor.processActionPerform(S2TilesRequestProcessor.java:122)
at org.seasar.struts.processor.AcceptorImpl.process(AcceptorImpl.java:126)
at org.seasar.struts.processor.S2TilesRequestProcessor.process(S2TilesRequestProcessor.java:61)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.seasar.tuigwaa.util.filter.TgwFilter.doFilter(TgwFilter.java:67)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.seasar.tuigwaa.util.filter.EncodingFilter.doFilter(EncodingFilter.java:65)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.seasar.tuigwaa.util.filter.ForwardFilter.doFilter(ForwardFilter.java:83)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.seasar.struts.filter.S2StrutsFilter.doFilter(S2StrutsFilter.java:45)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.seasar.framework.container.filter.S2ContainerFilter.doFilter(S2ContainerFilter.java:60)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:432)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:833)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:639)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1285)
at java.lang.Thread.run(Unknown Source)