when i process a single partition in SQL Agent job,another partition disappears...

In the partition source ,I use query binding,a partition for a month,like this:

select ... FROM [dbo].[mds_XX_post_hour]
WHERE substring(cast(dt as varchar),1,6)='201307'

my partition process :

<Batch xmlns="http://schemas.microsoft.com/analysisservices/2003/engine">
  <Parallel>
    <Process xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ddl2="http://schemas.microsoft.com/analysisservices/2003/engine/2" xmlns:ddl2_2="http://schemas.microsoft.com/analysisservices/2003/engine/2/2" xmlns:ddl100_100="http://schemas.microsoft.com/analysisservices/2008/engine/100/100" xmlns:ddl200="http://schemas.microsoft.com/analysisservices/2010/engine/200" xmlns:ddl200_200="http://schemas.microsoft.com/analysisservices/2010/engine/200/200">
      <Object>
        <DatabaseID>XXX</DatabaseID>
        <CubeID>XXX</CubeID>
        <MeasureGroupID>Post Hour</MeasureGroupID>
        <PartitionID>Post_2</PartitionID>
      </Object>
      <Type>ProcessFull</Type>
      <WriteBackTableCreation>UseExisting</WriteBackTableCreation>
    </Process>
  </Parallel>
</Batch>

when i direct process the xmla,that is OK. But in SQL Agent job step,after is executed,data of another partition Post_1(June) disappeared.

sorroy  for my english language ability...