Do you mean that when you create a new blank document, it opens with the
insertion point in the header pane? I have seen reports of this before and
don't know what could cause it.
First, be sure it's really opening in the header pane and that the problem
is not just that you have the white space hidden (see
http://sbarnhill.mvps.org/WordFAQs/WhiteSpace.htm).
If that's not the problem, try the solution offered at
http://word.mvps.org/FAQs/General/SaveViewAndZoom.htm.
If that doesn't solve the problem, look at Tools | Macro | Macros to see if
their is an AutoNew macro that might be causing the problem.
Note that uninstalling and reinstalling rarely helps with such problems
because it does not touch Normal.dot or the Registry, which are two of the
most common sources of problems.