black stripes over word document when viewing in large doc zoom >

hi

platform : winXP pro + work 2K w/ SP3(of word).

when i scroll through a word document in a zoom size > 85% (of the document
view), like page width view i start to see in some pages blck thick stripes
over the document left to right,
these stripes are not real , they disappear when i reduce the document zoom
size,
but they cover the text and very annoying.

2nd phenomena i encounter is that changes in the document are not updated or
seem gibrish , i have to scroll the document up or down in order to see the
changes right.

things i already tried:
1. re-install office.
2. updated display adapter driver to the newest.
3. change the display adapter card.

help will be appreciated.

best regards

Guy L.