I\'m working on a site which I havent coded from scratch and in firebug the css files are being displayed as: style.css.pagespeed.ce.5d2Z68nynm.css with the pagespeed extens
Another thing you can do is leave *mod_pagespeed* out of your ssl.conf file. This way, you can access your site via https for development.
Kind of a hack, I know, but it's handy in some cases where you need to make very quick changes.