Installing aspell-nl seems to fix this. Not only that, but installing another language (with System -> Admin -> Language-support) now adds a dictionary as well. This has either been fixed _or_ there is difference with the amount language-support with the desktop-installer and language-setup.
** Changed in: firefox (Ubuntu) Status: Confirmed => Fix Released -- Firefox spell checker has no dutch dictionary, eventhough I install dutch language support. https://launchpad.net/bugs/66017 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs