Board keeps eating my newlines

When typing a post with newlines in it and clicking "Preview Post", the newlines got stripped out of the post. Tried adding < b r / > (with fewer spaces) on the end of the newlines, and that seemed to work, but then those were stripped out of the post on preview. Short of hacking together a user script, is there a way to get newlines to stick? (Maybe disabling HTML parsing in my posts, but I don't see how to do that?) Thanks.