Migration problem between 1.3 and 1.6

While migrating a DB from XE 1.3 to XE 1.6, I get this exception, and migration stops :
2009-01-23 18:16:37,921 http://parisjug.jugsfarm.xwiki.com/xwiki/bin/view/Main/ [TP-Processor3] WARN util.JDBCExceptionReporter - SQL Error: 0, SQLState: 22001
2009-01-23 18:16:37,921 http://parisjug.jugsfarm.xwiki.com/xwiki/bin/view/Main/ [TP-Processor3] ERROR util.JDBCExceptionReporter - Data truncation: Data too long for column 'XWR_PATCH' at row 1
2009-01-23 18:16:37,922 http://parisjug.jugsfarm.xwiki.com/xwiki/bin/view/Main/ [TP-Processor3] ERROR .AbstractFlushingEventListener - Could not synchronize database state with session
org.hibernate.exception.DataException: could not update: [com.xpn.xwiki.doc.rcs.XWikiRCSNodeContent#component[docId,version1,version2]

]
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:77)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2430)
at org.hibernate.persister.entity.AbstractEntityPersister.updateOrInsert(AbstractEntityPersister.java:2312)
at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2612)
at org.hibernate.action.EntityUpdateAction.execute(EntityUpdateAction.java:96)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:168)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:298)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1000)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:338)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106)
at com.xpn.xwiki.store.XWikiHibernateBaseStore.endTransaction(XWikiHibernateBaseStore.java:866)
at com.xpn.xwiki.store.XWikiHibernateBaseStore.endTransaction(XWikiHibernateBaseStore.java:837)
at com.xpn.xwiki.store.XWikiHibernateBaseStore.execute(XWikiHibernateBaseStore.java:1057)
at com.xpn.xwiki.store.XWikiHibernateBaseStore.executeWrite(XWikiHibernateBaseStore.java:1098)
at com.xpn.xwiki.store.migration.hibernate.R6079XWIKI1878Migrator.migrate(R6079XWIKI1878Migrator.java:93)
at com.xpn.xwiki.store.migration.hibernate.AbstractXWikiHibernateMigrator.migrate(AbstractXWikiHibernateMigrator.java:39)
at com.xpn.xwiki.store.migration.AbstractXWikiMigrationManager.startMigrations(AbstractXWikiMigrationManager.java:288)
at com.xpn.xwiki.store.migration.AbstractXWikiMigrationManager.startMigrationsForDatabase(AbstractXWikiMigrationManager.java:196)
at com.xpn.xwiki.store.migration.AbstractXWikiMigrationManager.startMigrations(AbstractXWikiMigrationManager.java:127)
at com.xpn.xwiki.XWiki.initXWiki(XWiki.java:715)
at com.xpn.xwiki.XWiki.<init>(XWiki.java:655)
at com.xpn.xwiki.XWiki.getMainXWiki(XWiki.java:315)
at com.xpn.xwiki.XWiki.getXWiki(XWiki.java:386)
at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:135)
at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:115)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.xpn.xwiki.wysiwyg.server.filter.ConversionFilter.doFilter(ConversionFilter.java:94)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.xpn.xwiki.web.SavedRequestRestorerFilter.doFilter(SavedRequestRestorerFilter.java:287)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.xpn.xwiki.web.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:112)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:190)
at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:283)
at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:767)
at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:697)
at org.apache.jk.common.ChannelSocket$SocketConnection.runIt(ChannelSocket.java:889)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:690)
at java.lang.Thread.run(Unknown Source)
Caused by: java.sql.BatchUpdateException: Data truncation: Data too long for column 'XWR_PATCH' at row 1
at com.mysql.jdbc.PreparedStatement.executeBatchSerially(PreparedStatement.java:1257)
at com.mysql.jdbc.PreparedStatement.executeBatch(PreparedStatement.java:943)
at org.apache.commons.dbcp.DelegatingStatement.executeBatch(DelegatingStatement.java:294)
at org.apache.commons.dbcp.DelegatingStatement.executeBatch(DelegatingStatement.java:294)
at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:48)
at org.hibernate.jdbc.BatchingBatcher.addToBatch(BatchingBatcher.java:34)
at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2408)
... 56 more

I can provide the databse on demand.