Error 'Could not find child' deleting a document

In the nightly performance test one delete action(of in total 528 deletes) failed. In the stacktrace ( http://10.10.110.7/job/CMS%20Workflow/354/consoleFull) :

[INFO] [talledLocalContainer] 23.02.2014 16:34:50 ERROR [org.onehippo.repository.scxml.SCXMLWorkflowExecutor.handleException():128] Could not find child 52887135-0bb5-4ab4-97b9-17b3814b1521 of node d7584744-06bb-49bb-83ee-86a31d6d0449
[INFO] [talledLocalContainer] org.hippoecm.repository.api.WorkflowException: Could not find child 52887135-0bb5-4ab4-97b9-17b3814b1521 of node d7584744-06bb-49bb-83ee-86a31d6d0449
[INFO] [talledLocalContainer] at org.onehippo.repository.documentworkflow.task.AbstractDocumentTask.execute(AbstractDocumentTask.java:95)
[INFO] [talledLocalContainer] at org.onehippo.repository.scxml.AbstractWorkflowTaskAction.doExecute(AbstractWorkflowTaskAction.java:62)
[INFO] [talledLocalContainer] at org.onehippo.repository.scxml.AbstractAction.execute(AbstractAction.java:75)
[INFO] [talledLocalContainer] at org.apache.commons.scxml2.semantics.SCXMLSemanticsImpl.executeActions(SCXMLSemanticsImpl.java:223)
[INFO] [talledLocalContainer] at org.apache.commons.scxml2.SCXMLExecutor.triggerEvents(SCXMLExecutor.java:133)
[INFO] [talledLocalContainer] at org.apache.commons.scxml2.SCXMLExecutor.triggerEvent(SCXMLExecutor.java:162)
[INFO] [talledLocalContainer] at org.onehippo.repository.scxml.SCXMLWorkflowExecutor.triggerAction(SCXMLWorkflowExecutor.java:216)
[INFO] [talledLocalContainer] at org.onehippo.repository.scxml.SCXMLWorkflowExecutor.triggerAction(SCXMLWorkflowExecutor.java:169)
[INFO] [talledLocalContainer] at org.onehippo.repository.documentworkflow.DocumentWorkflowImpl.delete(DocumentWorkflowImpl.java:211)
...
[INFO] [talledLocalContainer] Caused by: javax.jcr.InvalidItemStateException: Could not find child 52887135-0bb5-4ab4-97b9-17b3814b1521 of node d7584744-06bb-49bb-83ee-86a31d6d0449
[INFO] [talledLocalContainer] at org.apache.jackrabbit.core.ItemManager.getDefinition(ItemManager.java:207)
[INFO] [talledLocalContainer] at org.apache.jackrabbit.core.ItemSaveOperation.validateTransientItems(ItemSaveOperation.java:439)
[