See http://support.microsoft.com/?kbid=303507 "Black bar appears
across the page when you type text in Word 2002".

Charlene wrote:
The line that the cursor is on becomes completely shaded in black, so that it
is impossible to read what I am typing. If I navigate around the document by
scrolling up or down, the shading goes away until I type again, so I think it
is linked to where the cursor is in the document. How can I fix this?