Import from 3.4.5 to 3.5.4 fails with "unique constraint violation"

2011-05-23 11:20:30,191 ERROR [Importing data task] [sf.hibernate.util.JDBCExceptionReporter] logExceptions ORA-00001: unique constraint (CONFLUENCE_3_5_4.CP_UNIQUE_USER_GROUPS) violated

 -- referer: https://our.server/confluence/setup/setup-restore-start.action | url: /confluence/setup/setup-restore-local.action | userName: anonymous | action: setup-restore-local
2011-05-23 11:20:30,191 ERROR [Importing data task] [sf.hibernate.impl.SessionImpl] execute Could not synchronize database state with session
 -- referer: https://our.server/confluence/setup/setup-restore-start.action | url: /confluence/setup/setup-restore-local.action | userName: anonymous | action: setup-restore-local
2011-05-23 11:20:30,191 ERROR [Importing data task] [confluence.importexport.xmlimport.DefaultImportProcessor] persist Error while saving object: Imported[com.atlassian.confluence.labels.Label] [Id[id]=24412184, Property[name]=permissions, Property[owner]=, Property[namespace]=global, Property[creationDate]=2009-08-21 09:44:59.000, Property[lastModificationDate]=2009-08-21 09:44:59.000]
 -- referer: https://our.server/confluence/setup/setup-restore-start.action | url: /confluence/setup/setup-restore-local.action | userName: anonymous | action: setup-restore-local
2011-05-23 11:20:30,191 ERROR [Importing data task] [confluence.importexport.xmlimport.BackupImporter] importEntities Cannot import the entities: 
 -- referer: https://our.server/confluence/setup/setup-restore-start.action | url: /confluence/setup/setup-restore-local.action | userName: anonymous | action: setup-restore-local
com.atlassian.confluence.importexport.ImportExportException: Unable to complete import: Error while importing backup: Hibernate operation: could not insert: [com.atlassian.confluence.security.ContentPermission#38502405]; SQL []; ORA-00001: unique constraint (CONFLUENCE_3_5_4.CP_UNIQUE_USER_GROUPS) violated
; nested exception is java.sql.SQLIntegrityConstraintViolationException: ORA-00001: unique constraint (CONFLUENCE_3_5_4.CP_UNIQUE_USER_GROUPS) violated

	at com.atlassian.confluence.importexport.xmlimport.DefaultXmlImporter.doImport(DefaultXmlImporter.java:61)
	at com.atlassian.confluence.importexport.xmlimport.BackupImporter.importEntities(BackupImporter.java:212)
	at com.atlassian.confluence.importexport.xmlimport.BackupImporter.importEverything(BackupImporter.java:173)
	at com.atlassian.confluence.importexport.xmlimport.FileBackupImporter.importEverything(FileBackupImporter.java:103)
	at com.atlassian.confluence.importexport.xmlimport.BackupImporter.doImportInternal(BackupImporter.java:104)
	at com.atlassian.confluence.importexport.Importer.doImport(Importer.java:71)
	at com.atlassian.confluence.importexport.DefaultImportExportManager.importAs(DefaultImportExportManager.java:74)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:304)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)
	at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
	at $Proxy83.importAs(Unknown Source)
	at com.atlassian.confluence.importexport.actions.ImportLongRunningTask.runInternal(ImportLongRunningTask.java:55)
	at com.atlassian.confluence.util.longrunning.ConfluenceAbstractLongRunningTask.run(ConfluenceAbstractLongRunningTask.java:21)
	at java.lang.Thread.run(Thread.java:619)
Caused by: org.springframework.dao.DataIntegrityViolationException: Hibernate operation: could not insert: [com.atlassian.confluence.security.ContentPermission#38502405]; SQL []; ORA-00001: unique constraint (CONFLUENCE_3_5_4.CP_UNIQUE_USER_GROUPS) violated
; nested exception is java.sql.SQLIntegrityConstraintViolationException: ORA-00001: unique constraint (CONFLUENCE_3_5_4.CP_UNIQUE_USER_GROUPS) violated

	at com.atlassian.confluence.importexport.xmlimport.parser.BackupParser.endElement(BackupParser.java:53)
	at org.apache.xerces.parsers.AbstractSAXParser.endElement(Unknown Source)
	at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanEndElement(Unknown Source)
	at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
	at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
	at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
	at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
	at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
	at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
	at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
	at org.apache.xerces.jaxp.SAXParserImpl.parse(Unknown Source)
	at javax.xml.parsers.SAXParser.parse(SAXParser.java:198)
	at com.atlassian.confluence.importexport.xmlimport.DefaultXmlImporter.parseBackup(DefaultXmlImporter.java:93)
	at com.atlassian.confluence.importexport.xmlimport.DefaultXmlImporter.doImport(DefaultXmlImporter.java:45)
	... 20 more
Caused by: org.springframework.dao.DataIntegrityViolationException: Hibernate operation: could not insert: [com.atlassian.confluence.security.ContentPermission#38502405]; SQL []; ORA-00001: unique constraint (CONFLUENCE_3_5_4.CP_UNIQUE_USER_GROUPS) violated
; nested exception is java.sql.SQLIntegrityConstraintViolationException: ORA-00001: unique constraint (CONFLUENCE_3_5_4.CP_UNIQUE_USER_GROUPS) violated

	at org.springframework.jdbc.support.SQLStateSQLExceptionTranslator.translate(SQLStateSQLExceptionTranslator.java:110)
	at org.springframework.orm.hibernate.HibernateAccessor.convertJdbcAccessException(HibernateAccessor.java:364)
	at org.springframework.orm.hibernate.HibernateAccessor.convertHibernateAccessException(HibernateAccessor.java:351)
	at org.springframework.orm.hibernate.HibernateTemplate.execute(HibernateTemplate.java:375)
	at org.springframework.orm.hibernate.HibernateTemplate.execute(HibernateTemplate.java:337)
	at com.atlassian.confluence.labels.persistence.dao.hibernate.HibernateLabelDao.findByLabel(HibernateLabelDao.java:79)
	at com.atlassian.confluence.labels.DefaultLabelManager.getLabel(DefaultLabelManager.java:426)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:304)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)
	at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
	at com.atlassian.spring.interceptors.SpringProfilingInterceptor.invoke(SpringProfilingInterceptor.java:16)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
	at $Proxy28.getLabel(Unknown Source)
	at com.atlassian.confluence.importexport.xmlimport.persister.ReflectiveObjectPersister.persist(ReflectiveObjectPersister.java:111)
	at com.atlassian.confluence.importexport.xmlimport.DefaultImportProcessor.persist(DefaultImportProcessor.java:42)
	at com.atlassian.confluence.importexport.xmlimport.DefaultImportProcessor.processObject(DefaultImportProcessor.java:32)
	at com.atlassian.confluence.importexport.xmlimport.parser.BackupParser.endElement(BackupParser.java:49)
	... 33 more
Caused by: java.sql.SQLIntegrityConstraintViolationException: ORA-00001: unique constraint (CONFLUENCE_3_5_4.CP_UNIQUE_USER_GROUPS) violated

	at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:440)
	at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:396)
	at oracle.jdbc.driver.T4C8Oall.processError(T4C8Oall.java:837)
	at oracle.jdbc.driver.T4CTTIfun.receive(T4CTTIfun.java:445)
	at oracle.jdbc.driver.T4CTTIfun.doRPC(T4CTTIfun.java:191)
	at oracle.jdbc.driver.T4C8Oall.doOALL(T4C8Oall.java:523)
	at oracle.jdbc.driver.T4CPreparedStatement.doOall8(T4CPreparedStatement.java:207)
	at oracle.jdbc.driver.T4CPreparedStatement.executeForRows(T4CPreparedStatement.java:1010)
	at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:1315)
	at oracle.jdbc.driver.OraclePreparedStatement.executeInternal(OraclePreparedStatement.java:3576)
	at oracle.jdbc.driver.OraclePreparedStatement.executeUpdate(OraclePreparedStatement.java:3657)
	at oracle.jdbc.driver.OraclePreparedStatementWrapper.executeUpdate(OraclePreparedStatementWrapper.java:1350)
	at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeUpdate(NewProxyPreparedStatement.java:105)
	at net.sf.hibernate.impl.NonBatchingBatcher.addToBatch(NonBatchingBatcher.java:22)
	at net.sf.hibernate.persister.EntityPersister.insert(EntityPersister.java:462)
	at net.sf.hibernate.persister.EntityPersister.insert(EntityPersister.java:436)
	at net.sf.hibernate.impl.ScheduledInsertion.execute(ScheduledInsertion.java:37)
	at net.sf.hibernate.impl.SessionImpl.execute(SessionImpl.java:2447)
	at net.sf.hibernate.impl.SessionImpl.executeAll(SessionImpl.java:2433)
	at net.sf.hibernate.impl.SessionImpl.execute(SessionImpl.java:2390)
	at net.sf.hibernate.impl.SessionImpl.autoFlushIfRequired(SessionImpl.java:1819)
	at net.sf.hibernate.impl.SessionImpl.getQueries(SessionImpl.java:1576)
	at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:1541)
	at net.sf.hibernate.impl.QueryImpl.list(QueryImpl.java:49)
	at com.atlassian.confluence.labels.persistence.dao.hibernate.HibernateLabelDao$1.doInHibernate(HibernateLabelDao.java:101)
	at org.springframework.orm.hibernate.HibernateTemplate.execute(HibernateTemplate.java:370)
	... 53 more