Tried what GöranJ proposed
- I installed Language Pack Install Helper 2,5
- I tried to configure it (not much out of configuration, but I could notice in the configuration part that Swedish was present).
- I then tried to open a gmail mail window, write something in swedish, right clicked on the words, still swedish is not a selectable dictionnary in the list. I have various english, german and french in that list that I've installed but thus not Swedish.
I also tried several times both before and after the Language Pack Install Helper 2,5 to install the swedish dictionnary. Booouuuh! :(