Do you have the language codes set right in the doctype? It should feature a two letter combination that represents Swedish like:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
Change the //EN in the tag to your language code. According to an article with the W3C, your choices are:
sv # Swedish
sv-fi # Swedish (Finland)
sv-se # Swedish (Sweden)
So if you choose Swedish (Sweden) you would replace it with //SV-SE.
And you will also have to set your character set to Swedish...and you should research this to make sure but one site tells me it should be:
<meta http-equiv="content-type" content="text/html; charset=iso-8859-1" />
But I'd check it out for sure to get it right.