If you have widow/orphan control activated (which is quite normal), that would require Word to move at least two lines of text to the next page.

Your particular issue might be addressed by changing the format of the footnote separator, the footnotes themselves, and/or your page setup. Since we haven't seen the document, we're not in a position to give more specific advice than I've already given.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]