htaccess error when turning Gzip on

I turned on (ticked and saved) the 3 checkboxes on the cache settings page; Enable cache, Leverage browser caching and Enable gzip compression. This immediately gave me the 500 internal error.

It turns out that the error was coming from the htaccess file modification. A few times where WP Performance made the changes in the file it added a comment like ‘# WPP Expire start’ on the same line as </IfModule> and that broke the site.

After testing it a bit, it doesn’t seem to happen every time, but is this something that you can make sure is avoided?