Here's a heads-up to anyone experiencing difficulties using supplemental dictionaries in Thunderbird (i.e. any dictionaries you install, like en-GB for example). This used to work fine on FC4, but for some reason, under FC5, the new supplemental dictionaries don't work (thinks every word is misspelt). I did some digging, and it turns out that the 3 files it installs have their attributes set to 400, i.e. read only by owner, which was root, where it *should* be 644, i.e. owner(read/write), group(read), other(read). In the case of the en-GB dictionary, the 3 files in question are: en-GB.aff en-GB.dic README-en-GB.txt To make sure *all* Thunderbird dictionaries have the right attributes, run the following command as root: chmod 644 /usr/lib/thunderbird-`rpm -q --qf "%{VERSION}\n" \ thunderbird`/components/myspell/* PS - replace "chmod 644" with "ls -l" first, to make sure you've got the *right* files, before you mess up your filesystem by accident. That will also show you whether or not you need to change any attributes at all. Oh, and for those who are still stuck on how to install dictionaries on Thunderbird under Linux ... you need to run Thunderbird from a terminal *as root* to be able to install dictionaries, since they are written to a directory that unprivileged users don't have write access to. I don't recall reading any notice that warns Thunderbird users about that issue. http://www.mozilla.com/thunderbird/dictionaries.html - K.