http://bugs.winehq.org/show_bug.cgi?id=5264
--- Comment #37 from Rosanne DiMesio dimesio@earthlink.net 2009-11-26 11:58:32 --- Tested in wine-1.1.33-404-gac85305, Word 2003 Pro.
The error message mentioned in comment #5 is gone, and Wine now opens the full Equation Editor in a separate window when you select Insert=>Object=>Microsoft Equation 3.0.
The problem is, this is not the way it works in Windows (tested in XP). In Windows, selecting the Microsoft Equation 3.0 inserts a box in the original document, and opens the Equation Editor toolbar. You can then enter the equations directly in the box in the document, and when you close the toolbar, the equation is still displayed in the document.
In Wine, because the Equation Editor opens as separate app, equations are entered in the Equation Editor window, and they do not get inserted in the original document.