Yesterday Steve Souders, Chief Performance Yahoo!, released a new version of YSlow, the tool to help you improve the performances of your website.

Version 0.8 fixes a bug in the Firebug NET panel, where cached pages sometimes show up in the network monitor: here is a detailed explanation of problem and how to enable the fix.

They also fixed a small problem that caused stylesheets with mixed case not to be recognized as being in the head of the document (rule 5).

If you already installed YSlow, you already saw the update via the Firefox auto-update feature, otherwise you can install it from Mozilla Add-ons site.

As side note to this topic, I got the High Performance Web Sites (Essential Knowledge for Front-End Engineers) book, and I'll start to read as soon as I find the time to do it.