DeletionServiceImpl fails to delete stage due to NPE

2014-04-22 23:37:48,783 INFO [QuartzScheduler_Worker-10] [DeletionServiceImpl] Deleting 4006 stage(s) marked for deletion
2014-04-22 23:37:48,785 INFO [QuartzScheduler_Worker-10] [PlanManagerImpl] Removing 1 stage(s) for plan AMKT-TRUNK31
2014-04-22 23:37:48,814 ERROR [QuartzScheduler_Worker-10] [DeletionServiceImpl] Unable to complete delayed deletion: 
java.lang.NullPointerException
        at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:187)
        at com.atlassian.bamboo.utils.BambooPredicates$HasBambooObjectEqualIdPredicate.apply(BambooPredicates.java:306)
        at com.atlassian.bamboo.utils.BambooPredicates$HasBambooObjectEqualIdPredicate.apply(BambooPredicates.java:295)
        at com.google.common.collect.Iterators.removeIf(Iterators.java:213)
        at com.google.common.collect.Iterables.removeIf(Iterables.java:184)
        at com.atlassian.bamboo.plan.AbstractChain.removeStage(AbstractChain.java:76)
        at com.atlassian.bamboo.plan.PlanManagerImpl.removeStages(PlanManagerImpl.java:448)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        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 com.atlassian.bamboo.security.acegi.intercept.aopalliance.AuthorityOverrideMethodSecurityInterceptor.invoke(AuthorityOverrideMethodSecurityInterceptor.java:29)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
        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 com.sun.proxy.$Proxy47.removeStages(Unknown Source)
        at com.atlassian.bamboo.deletion.DeletionServiceImpl.executeDelayedDeletion(DeletionServiceImpl.java:502)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:304)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)
        at com.atlassian.bamboo.security.acegi.intercept.aopalliance.AuthorityOverrideMethodSecurityInterceptor.invoke(AuthorityOverrideMethodSecurityInterceptor.java:29)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
        at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
        at com.sun.proxy.$Proxy106.executeDelayedDeletion(Unknown Source)
        at com.atlassian.bamboo.deletion.DeletionServiceJob.execute(DeletionServiceJob.java:26)
        at org.quartz.core.JobRunShell.run(JobRunShell.java:202)
        at com.atlassian.bamboo.utils.BambooRunnables$1.run(BambooRunnables.java:49)
        at com.atlassian.bamboo.security.ImpersonationHelper.runWith(ImpersonationHelper.java:31)
        at com.atlassian.bamboo.security.ImpersonationHelper.runWithSystemAuthority(ImpersonationHelper.java:20)
        at com.atlassian.bamboo.security.ImpersonationHelper$1.run(ImpersonationHelper.java:52)
        at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:525)