When I add a x-httpd-php5-source handler and try to point .phps files to the that handler, I get a strange error that turns up nothing in Google ("Handler application/x-httpd-php5-source not found"). Except if I actually enter a Handler it doesn't know, Apache should (and does) just ignore it. Look like syntax-highlighting is poorly implementing in suPHP. I recommend trying this hack to get around the issue (the FAQ they source is outdated to show that suPHP can't handle syntax highlighting is outdated, though; suPHP claims it is supported as of version 0.7.0).