In \share\translations\swe-SE\translation.ts, in the context design/admin/parts/my/menu the translation for the word "on" is "den" wich is not correct in this case. It should be "på".

Current:

    <message>
        <source>on</source>
        <translation>den</translation>
    </message>

Should be:

    <message>
        <source>on</source>
        <translation>på</translation>
    </message>