Adminhtml Grid appears twice

If you create a custom adminhtml grid and you get the resulting data 2x after you use a column header or filter, the problem is with the xml.

The solution is to remove part of the xml.  The red text (output="toHtml") on the nested block is the code you need to remove

***** BAD XML that is showing the block twice *****
<adminhtml_flat_entry_grid>
    <block type="core/text_list" name="root" output="toHtml">
        <block type="engine23_blog/adminhtml_flat_entry_grid" name="blog_ajax_grid" output="toHtml"/>
    </block>
</adminhtml_flat_entry_grid>

**** Correct XML to remove the extra block when filters/sorting is used ****

<adminhtml_flat_entry_grid>
    <block type="core/text_list" name="root" output="toHtml">
        <block type="engine23_blog/adminhtml_flat_entry_grid" name="blog_ajax_grid" />
    </block>
</adminhtml_flat_entry_grid>