Excel Formatting not staying consistent.

Version: Excel 2010

I have a rather large spreadsheet and have paged the document exactly as we need it, however, when I close the file and re-open it, the paging has changed. It is very difficult and time consuming when I am constantly needing to repage.

Any ideas why this is happening?

Have you saved the spreadsheet after setting up the paging? If that's all you've changed, Excel won't prompt to save when you close it, but it also won't remember the paging changes unless you've saved.