Created attachment 105701 [details]
A simple Word 2003 Document with a working Merge field.  When resaved you will see the merge field will lose it's highlight and cease being able to merge.

Problem description: 

Steps to reproduce:
1. ....Open and existing Word 2003 Document with a Merge Field
2. ....Make Resave the document and chose Word 2003
3. ....Check the documents Merge Field and find it no longer functions

Current behavior:
The Merge Field turns to text and loses it's database cabilities.  When the merge function runs the field is ignored and nothing the expected items do not merge.

Expected behavior:
The field should show as highlighted as when first opened.  When it's saved with or without any changes made the highlight of the field is lost and the merge ceases working.

              
Operating System: Windows 8
Version: 4.2.6.2 release