ListGrid - Hidden FileItem Shows Up

[pingten]

I have an SQLDB table <images>, load it into a ListGrid, set the field <Title> as editable. When I double-click one <Title> cell to try changing its value, a hidden FileItem, with a TextItem and a Button <Browse>, shows up at the left-top corner of the ListGrid. Please view the attached screen-shot. Where the hell it comes from? How I can force this FileItem NOT show up? It's quite annoying to the user. Please help.

Test.java

    Window wnd = new Window();

    ListGrid lgTest = new ListGrid();
    DataSource ds = DataSource.get("dsTest");
    lgTest.setDataSource(ds);
    lgTest.setAutoFetchData(true);

    wnd.addChild(lgTest);
    wnd.show();

Test.ds.xml

<DataSource ID="dsTest" dataFormat="iscServer" serverType="sql" tableName="images">

    <fields>
        <field name="id" type="sequence" hidden="true" primaryKey="true"/>
        <field name="title" title="Title" type="text" canEdit="true"/>
        <field name="image" title="Download" type="binary" canFilter="false"/>
        <field name="image_filename" title="Name" type="text"/>
        <field name="image_filesize" title="Size" type="integer"/>
        <field name="image_date_created" title="Upload Time" type="datetime"/>
    </fields>

</DataSource>

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[Environment]
SmartGWT Version: SC_SNAPSHOT-2012-01-05_v8.2p/PowerEdition Deployment (built 2012-01-05)
GWT Version: 2.4.0
OS: Windows 7 Premium
Browser: IE 9.0.8112.12461, FF 9.0.1

[Isomorphic]

Set canEdit=false on the ListGridField for the field of type="binary".