I start by assuming you have 'Picture placeholders' unchecked in  
Options/view/show.
If that is the case you may be dealing with a microsoft security patch that
does not seem to bother many people but can cause what you describe.  
If the options setting does not help you may find the source of your problem
below (an excerpt from an answer to another post)  Good luck.

". . . Office 2003 'security  update' that Microsoft includes in the
standard Windows updates.  It has caused our templates to have the same
problem as you decribe.  
We are able to fix the problem by changing our code that inserts the images.
The update is "Security Update for Word 2003 (KB917334)"  
You can see the update history of the computer by clicking on Windows Update
(in All Programs) then click on 'Review your update history'. . ."