I use Xubuntu 12.04. I uninstalled Firefox and now use Google Chrome version 19.xxx.
To solve this problem, I tried:
the "default apps" under settings and
sudo update-alternatives --config x-www-browser
Neither of these worked. Does anybody have an alternative solution for this?
--> Solution: I used the "sudo gedit /usr/share/applications/defaults.list" tip from 天使の and searched for firefox in the whole document! Everytime I found "firefox" I replaced it with "google-chrome.desktop". I also used the "default apps" menu to change it to google-chrome. And now it works.. I hope it helps some other ;-)