I used to receive many source documents with this language problem while I was creating technical documentation at work. Early in each document, Word found our company address on San Ignacio Avenue in San Jose, California and constantly reset our English text as Portuguese (Brazil).

In your Normal.dotx template, try to reset the language for the Normal style (and all styles not based on Normal), or for an existing document, just select the entire document with CTRL+A.
Find wherever you set the language in Word 2007 (in my Word 2003, it's on the menu at Tools > Language > Set Language).
Set the language to whatever is appropriate [I use English (U.S.) in my location.]
MOST IMPORTANT: Clear any checkbox that says: Detect language automatically. (If the box is shaded, click it repeatedly until the checkbox box is clear (that is, has no check mark.)

As to the page not breaking where you want, I can't say anything definitive. But, if you are using manual page breaks, try instead setting a paragraph format. In the Paragraph dialog box, click the Line and Page Breaks tab, and under the Pagination group, select the check box labeled Page break before. That should force the paragraph to start on a new page.