I have previously had problems with CSS and JS GZIP compression working properly. I was plagued by the missing "gzip" extension problem which resulted in the site being unstyled in certain browsers. For example it would output "style.css." (note the extra "." on the end) instead of "style.css.gzip".
I just did some testing after upgrading to WP 3.3.1, deactivated and uninstalled W3TC, reinstalled W3TC 0.9.2.4. Now GZIP appears to be working according to webpagetest.org and another similar site. Although there is not a "gzip" extension on the css files. For example it now outputs "style.css" (no extra period) instead of "style.css.gzip".
Can anyone please confirm if this new behavior is correct?