Mine were! It looked like some kind of serif font was being substituted for fonts that were sans-serif under Windows. We’ll the fix is very simple. I hope this helps someone.
- Close your browser.
- Open a terminal.
- sudo apt-get install msttcorefonts
- Open your browser.
- You should be good to go. Enjoy!

Unfortunately, this won’t fix anything. Font rendering is broken in Firefox 3 – even if the Microsoft fonts are installed correctly. It seems to be a Firefox 3 problem, as these problems also exist on Ubuntu Gutsy.
@Tobias
There was a significant difference on both of my machines after running this command.
Great! Works!!!
This solution worked perfectly for me (Ubuntu Hardy and FF3). Thanks
this was great…ran the code and couldn’t be happier