Page Numbering being reset in

I running on Windows 7 x64. I’ve got a header with the page numbr field in the top left of my document. After page 9, the next number used is page 1. I know that it is actually “1” (and not a “10” shifted too far to the right) because:
The next page is 2, then 3, (reflecting the fact that the count simply got reset to 1 after reaching 9)
and the table of contents reflects the reset counter value.

There are many reasons why this could be the case. Which file format (ODT, DOC, DOCX) are you using? Has the document been edited using other word processing software? Does the document contain any sections or defined page breaks? It is likely the problem related to poorly defined page styles as your question here indicates.