Need help w Word 2010 page size

[Ruth]

I am doing my final edit on a 300 pg manuscript and have never formatted for any page size except for the default 8.5 x 11. I have quite a few section breaks throughout. I have one page that has adopted a 8.5 x 14 legal format and I can not force it back into 8.5 x 11. When I isolated this problem page with section breaks and try to select that one page and change it using the simple page size menu, it gives me the message "increasing left margin causes first column to become too narrow in some sections having unevenly spaced columns". I have no columns in this sections and did not try to change the left margin. What else can I try? Please help