Change in handling of mso flags in HTML documents between INSO 8.3.5 and 8.3.7

We are using the INSO filters to parse HTML files. In these files there are header of the form:

<!--[if gte mso 9]><xml>

<mso:CustomDocumentProperties>

<mso:BBC_x0020_Subjects_x0020_2_Score msdt:dt="string">Addiction Addiction Addiction Addiction Addiction Chamber music Chamber music Chamber music Chamber music Drugs use and abuse Drugs use and abuse Drugs use and abuse Drugs use and abuse </mso:BBC_x0020_Subjects_x0020_2_Score>

</mso:CustomDocumentProperties>

</xml><![endif]-->

In version 8.3.5, the  INSO filter ignored these and so did not return the contents as text.

In version 8.3.7, the  INSO filter is returning the contents of the tags as text. As this text is not displayed as part of the web page, we do not want it returned as text.