I hope this is the right forum, as I can't be sure if the problem is thunderbird or the FC5 distribution I'm using. First off thunderbird doesn't allow you to install non US dictionaries easily when running on linux. You have to copy the dictionary files over manually under root or log in as root and use the thunderbird facility. Then it works but as soon as I update thunderbird using yum, the dictionaries are not copied over into the new version folders in /usr/lib/thunderbird-x.x.x.x/components/myspell (there is a new x.x.x.x with each version). This means you have to do it all over again.
It is possible that there is some manifest file that needs tweaking to make this operate properly but I don't know which if any file that'd be. Anyway, it seems troublesome to have to reconfigure after every update, especially as I have two home computers. So far I've come up with a short script that does the copy but I still have to update the version numbers each time. It seems from my end as if no-one outside the US actually uses thunderbird for serious email on linux. I tried evolution and was looking forward to its wider features and possibility of syncing across computers but have found it very slow, on my 1.3 pentium laptop it takes around 20 seconds just to tab between address fields! So I really would like to get thunderbird running without hassles.. I am posting this hoping either someone has a good work around for this or else someone at fedora / mozilla will take it on board.
Thanks
Jacek

I hope this will help. I've taken to getting firefox direct from Mozilla's directory rather than the website because I can then use a downloader other than firefox. I always get the en-GB version.

Earlier this week I got Thunderbird the same way for the first time. It's a tar.gz file which you place where you want the Thunderbird directory. You then use the command tar -xzvf thunderbird-1.5.0.4.tar.gz as root (cd to the file location first). It creates a directory named thunderbird which contains the command file thunderbird. It really could not be simpler. You need to add any menu command or icon you want and alter file associations. If you're using kde add %u to the menu command.

Installers for a number of languages are listed. Start here by selecting the version you want.

A thousand apologies. I spoke too soon. I filed a thread on the Mozillanine forums. My problem was different - I had not realised the need to install dictionaries as root.

As for updating, I have not faced that yet, obviously. Each time I install a new version of Firefox, I have to remember to extract the plugins, components and system-wide extensions before deleting the old directory. Incidentally, I found a more official link for so-called language versions.