Which extension did you use? FF or Chrome? I get different from both and they claim that compression isn't on certain files when it is. The PS site shows 100 (which is what outside scores are) but the browser tools show the same pages at 91 to 93. My cases are the opposite of what you see, the browser plugins are inaccurate.
Str82u - I was using Chrome. I appreciate the input on the plugins.
Hoople - Thanks - I've been learning about the waterfall displays over the last couple of months. I'm glad you mentioned the social plug ins. I had one a while back that was really slowing the site down. I'll revisit that are.
Try gtmetrix DOT com and pay attention to the waterfall reporting.
We normally don't discuss specific tools here to avoid self promotion, but I'm making an exception for this discussion. Gtmetrix is already mentioned in our Favorite SEO Tools thread [webmasterworld.com]. It's been one of my go-to tools for a few years. I agree that it is excellent, especially the waterfall breakdown for every page element.