Magento 1.9 – Dataflow Profile Export with Duplicate SKUs

after I updated my magento store to the latest version 1.9.2.1 I get into trouble regarding to the export of products with the dafalow profile export.

With every export I got duplicate entries in my csv file and don´t know why. In my product database I have no duplicate entries.
If I use the normal export mechanism with "export -> export products" I don´t get duplicate sku entries.

Does someone has the same issue with the dataflow profile?

I just created a new profile with only the sku in it.

<action type="catalog/convert_adapter_product" method="load">
    <var name="store"><![CDATA[0]]></var>
    <var name="filter/type"><![CDATA[simple]]></var>
</action>

<action type="catalog/convert_parser_product" method="unparse">
    <var name="store"><![CDATA[0]]></var>
    <var name="url_field"><![CDATA[0]]></var>
</action>

<action type="dataflow/convert_mapper_column" method="map">
    <var name="map">
        <map name="sku"><![CDATA[sku]]></map>
    </var>
    <var name="_only_specified">true</var>
</action>

<action type="dataflow/convert_parser_csv" method="unparse">
    <var name="delimiter"><![CDATA[,]]></var>
    <var name="enclose"><![CDATA["]]></var>
    <var name="fieldnames">true</var>
</action>

<action type="dataflow/convert_adapter_io" method="save">
    <var name="type">file</var>
    <var name="path">var/export</var>
    <var name="filename"><![CDATA[test.csv]]></var>
</action>

At the moment I have no idea how to solve this…

Small example with my csv export:

Sample CSV File