Race condition can create duplicate plan keys, causing Bamboo to fail to start

bamboo=# select build_id, buildkey from build;
 build_id | buildkey 
----------+----------
   393217 | TRUNK
  1507329 | JSTMVN
  1507330 | JSTMVN
   393218 | JOB1

@400000004e166cf406b6c1f4 2011-07-07 21:35:22,112 INFO [TP-Processor15] [AccessLogFilter] sysadmin POST https://sdog.jira.com/builds/build/admin/create/createPlan.action 103093kb
@400000004e166d0d0c95cb4c 2011-07-07 21:35:47,211 INFO [TP-Processor17] [AccessLogFilter] sysadmin POST https://sdog.jira.com/builds/build/admin/create/createPlan.action 114482kb
@400000004e166d1429151cdc 2011-07-07 21:35:54,685 INFO [TP-Processor15] [PlanCreationTemplate] Creating plan with key: JSTDEV-JSTMVN
@400000004e166d14301380b4 2011-07-07 21:35:54,803 INFO [TP-Processor15] [PlanCreationTemplate] New build created with key JSTDEV-JSTMVN
@400000004e166d1432779bec 2011-07-07 21:35:54,844 INFO [TP-Processor17] [PlanCreationTemplate] Creating plan with key: JSTDEV-JSTMVN
@400000004e166d1434823ce4 2011-07-07 21:35:54,852 ERROR [AtlassianEvent::0-BAM::EVENTS:pool-1-thread-6] [ChainExecutionManagerImpl] Could not start executing Plan 'JSTDEV-JSTMVN' as the plan did not have any stages defined
@400000004e166d14348244b4 2011-07-07 21:35:54,878 ERROR [TP-Processor17] [FiveOhOh] 500 Exception was thrown.
@400000004e166d143482489c org.springframework.dao.IncorrectResultSizeDataAccessException: query did not return a unique result: 2
@400000004e166d143482489c       at org.springframework.orm.hibernate.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:590)
@400000004e166d143482600c       at org.springframework.orm.hibernate.HibernateAccessor.convertHibernateAccessException(HibernateAccessor.java:353)
@400000004e166d14348263f4       at org.springframework.orm.hibernate.HibernateTemplate.execute(HibernateTemplate.java:375)
@400000004e166d14348267dc       at org.springframework.orm.hibernate.HibernateTemplate.execute(HibernateTemplate.java:337)
@400000004e166d1434826bc4       at com.atlassian.bamboo.plan.PlanHibernateDao.getPlanByKey(PlanHibernateDao.java:43)
@400000004e166d1434826fac       at sun.reflect.GeneratedMethodAccessor225.invoke(Unknown Source)
@400000004e166d1434826fac       at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
@400000004e166d143482871c       at java.lang.reflect.Method.invoke(Method.java:597)
@400000004e166d1434828b04       at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:304)
@400000004e166d1434828b04       at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182)
@400000004e166d1434828eec       at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)
@400000004e166d14348296bc       at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106)
@400000004e166d14348296bc       at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
@400000004e166d1434829aa4       at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
@400000004e166d1434829e8c       at $Proxy7.getPlanByKey(Unknown Source)
@400000004e166d1434829e8c       at com.atlassian.bamboo.plan.PlanManagerImpl.getPlanByKey(PlanManagerImpl.java:91)
@400000004e166d143482a274       at com.atlassian.bamboo.plan.PlanManagerImpl.getPlanByKey(PlanManagerImpl.java:85)