I have a fairly large document that has been scanned in by another person

however they missed one or two pages so I am having to import these from scan

When I try and do it the pages I add are a different size from the ones already in the file

I have tried setting the preferences to fit to A4 page and also same size as original

I am running Acrobat 5

Please does anybody know what I am doing wrong?!

Many thanks