Martin,
Swedish is not a language we support natively. You can create your own language strings by copying the /languages/en_GB/en_GB.mod_sclogin.ini file to your /languages/xx_YY directory for Swedish and make the updates there. If you create a Swedish language file, please feel free to post it back to us and we'll make sure it's included in the next release.
Hope that helps, but if you need anything else, just let us know.
Thanks,
Alex