From what I saw in the HTML it looks as though the non-breaking spaces were added, I'm confused as to why the <br> tags were also added. Why not let the menu conform to the user's screen size?
Replacing with white space should be plenty. If someone is really worried about links wraping on seperate lines why not just wrap each link with more than one word in <nobr> tags? Wouldn't that more accurately give the desired results as well as leave the job of formatting to the screen resolution?