Firefox's Error Console (Ctrl+Shift+J) collects lots of those style rule warnings. Some style rules only work in particular browsers (such as "filter" which is for IE), so Firefox notes that it doesn't recognize them. This information is more for the web developer's benefit than yours, since you can't do much to change the site.

To see serious errors and filter out the style warnings, click the Errors button at the top. Hopefully a lot less clutter.

Anyway, are you asking because something isn't working correctly?

yes it must be the site, although i get errors where firefox cannot find the server and i am not opening a new site just going from one page to another. thank you for your time it was appreciated.