Imbedded Word document scrolling (mis)behavior

I have an Excel 2003 workbook with a MS Word 2003 document embedded in one of the worksheets as an object. The document is several pages (if that matters). I am running on Vista.

While clicked into the embedded document and editing it (somewhere multiple pages into the document), the document is mysteriously repositioned (scrolled) to the top of the document. Sometimes it happens spontaneously with no action on my part...not even while I am moving the mouse. Sometimes it occurs while I am moving the cursor to a new spot in the document. If, immediately after the unwanted repositioning occurs, I merely type a key on the keyboard, the screen returns to its spot prior to the mysterious positioning and inserts the character as I wanted it. This behavior is VERY annoying.

The object window is big enough to display about 1 1/4 pages.

I guess I am looking for advice on a setting or some positioning of the object or resizing of the object's window....I realize that upgrading to a new Office version might "fix" the problem, but that is not an option.