Unable to rank issue with bucket is not the same as the expected next bucket error

2014-08-01 14:43:41,976 lexorank-executor-thread-0 ERROR      [service.lexorank.balance.LexoRankBalancingService] 
The new rank's bucket is not the same as the expected next bucket
java.lang.IllegalStateException: The new rank's bucket is not the same as the expected next bucket
	at com.atlassian.greenhopper.service.lexorank.balance.LexoRankBalanceOperation.moveMarkerRowToNextBucket(LexoRankBalanceOperation.java:356)
	at com.atlassian.greenhopper.service.lexorank.balance.LexoRankBalanceOperation.execute(LexoRankBalanceOperation.java:104)
	at com.atlassian.greenhopper.service.lexorank.balance.LexoRankBalancer.balanceFieldId(LexoRankBalancer.java:140)
	at com.atlassian.greenhopper.service.lexorank.balance.LexoRankBalancer.balanceFieldIds(LexoRankBalancer.java:89)
	at com.atlassian.greenhopper.service.lexorank.balance.LexoRankScheduledBalanceHandler.run(LexoRankScheduledBalanceHandler.java:47)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
	at java.util.concurrent.FutureTask.run(FutureTask.java:138)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:662)