I don't think that you can. Once it drops to the footer section, it sounds like Crystal believes it is done and doesn't need to repeat the header.
The only idea that comes to mind is to count the lines printed, but I have a feeling that the same issue can occur. You would probably need a count of the records and the lines. If you are 1 record from the end of the group, and at the bottom of the page, then force a page break, if there are more records, let Crystal do the formatting. It might look odd, but it will waste alot less paper...but it will be harder to code.