In admin/editconfig.php search for:

elseif ($config[language] == "spanish") {
$spanish = "SELECTED";
}

Then insert the following after that:

elseif ($config[language] == "swedish") {
$swedish = "SELECTED";
}

search for:
<option $spanish>spanish

after that insert
<option $swedish>swedish


The same problem can also be found i the perl-version.

Thanks again. Looks like I totally forgot to add this in.