cursor and newly typed text disappear

In word 2003 and outlook 2003 my cursor regularly disappears and then typed text cannot be seen unless I click my mouse pointer over that area. I sometimes starts if I backspace over text or hit enter for a new line. If I then put my mouse pointer over the cursor at the new line it appears and if I move the mouse pointer away it disappears after a few seconds.
This problem started when I switched from Office 2000 to Office 2003