I found recently that sometimes when I use an HTML & nbsp; it literally prints & nbsp; instead of a nonbreaking space.
Blogger is having trouble taking what I want to say, so I have to put a space between the ampersand and the nbsp; characters to get it to print correctly.
One instance that gave me trouble with the nbsp was between a td tag, even though I can include other HTML markup in between the opening and closing tag.
After some head scratching and reading I tried using a & #160; and that worked.
I guess HTML has two different ways of expressing non breaking spaces.