Headers in Word 2003

I have never seen this issue before so may be hard to explain but here goes:

I have a document with headers, footers and tables. When I double click the header it opens and spans to the bottom of the page covering my table. When I use the ruler to try to force it back up it won’t move. You wouldn’t think of this as much of an issue but it affects my table in odd ways, including not being able to adjust the top row’s height. Not all the headers do it, just some and it’s never the same ones.

I have searched multiple sites looking for something similar and can’t find anything. Any help is appreciated.