I am in the process of converting mail merge documents from .doc(word 2003-2007 format) to .docx format (word 2010). I open the .doc and click convert then save it as a .docx. It seems that the .docx file doesn't recognize that theres a header file anymore and instead it is using the first record in the datasource as the header and datasource. There is only one row in the datasource and the header source is in a table as suggested by microsoft.

Example: I have both versions open and go to the mail merge helper. I view the datasource in both.
.Doc
Owner_Name: Jon Doe
Organization: Some company
.Docx
Jon_Doe: Jon Doe
Some_Company: Some company

As you can see the header file isn't being recognized correctly in the .docx. Weird part is that if I relink the header file I can preview all the data correctly. But when I save it and re-open it, it doesn't recognize the header again and the data is still screwed up. I have tried this both on a network and on my desktop and I experience the same results.

Note: the header source is a doc(also tried it as a.docx) and the data source is a text file.

Thanks in advance.