Can't insert page break

Using Linux Mint 10, LibreOffice 3.50rc3; I would like to insert a page break at the end of a 135 page document. When I select Insert → Manual Break, the Page Break option is grayed out.
Ctrl-Enter doesn’t work, nor does pressing the Enter key to try to create a new page. Pressing the Enter key merely pushed the page number down without creating a new page.

What am I doing wrong?

I think that you are trying to insert a page break “in the footer of the page”. Make sure you’re in the main typing area before pressing control ENTER.