Display issue on screen only

[acog1]

Hi,
I am hoping someone can help me, I have a 44 page word document that I need to edit, however, when I open it, I cannot access pages 11 or 13, they are the only two in the document, they will not show on screen. I can print them and they print exactly as they should, but I need to edit them (they are calendar pages and I need to change the dates). I have tried adding extra pages and deleting pages, but this just moves the problem with the page.
I really don't understand it, the document cannot be corrupt as it wouldn't print correctly if that was the problem. I have tried Googling it, but can't find anything even remotely similar and I have always been able to access these pages in previous years.
I have included a print screen of what I see on screen and am hoping someone can explain what has happened and how to remedy it.
Thanks in advance.

[kilroy]

Can you attach a sample of the document?