When using OLE 1.0 objects in Word, you may experience problems in getting the presentation metafile (WMF) to update correctly if the document is not saved first. This problem occurs only with OLE 1.0 objects and not OLE 2.0.

See this page for the full article about the problem:
Unable to Update Metafile Presentation for OLE 1.0 Object in Word (2002/2003/2007)