I downloaded the 2.8.4 and uploaded all files and folders to my site.
I login to the Admin and:
1) With IE 7, it looks fine
2) In Google Chrome, it looks as if the CSS is not working. I just have a large list of unordered list tags with links. I upgraded to the most recent Google and the same thing occurs.
3) I have not tried with WINDOWS Firefox, yet, but since Chrome is based on Firefox, I suspect the same.
Thanks so much,