Thanks for contacting support.
I have tested the scenario using latest release of Aspose.Pdf for .NET 10.6.0
in Visual Studio 2012 application with target .NET Framework 4.0 running over Windows 7 (x64) and I am unable to notice any issue. As per my observations, the resultant DOCX is properly opening in MS Word 2010.
For your reference, I have also attached the resultant file generated over my end. Please take a look.
Open source PDF file<o:p></o:p>
Document pdfDocument = new Document(@"c:/pdftest/Merchant_Services_Application_Form.pdf");
save the output in MS DOCX format