The problem is that not all phone-number-lookup sources return UTF-8-codes. Herold-Austria, for example, returns ISO-8859 and there is one template from Germany which does it too (forgot which one it was).
I tested this workaround with Herold-Austria, Telefonabc-Austria, DeTEMedien-DE, Das-Telefonbuch-Germany, LocalTel-CH and it works.
Yet, if there is a foreign name (with special characters) listed in a german lookup-source, than the special character is not displayed correctly. One would have to add this character to the replace list, which currently contains only the german umlauts.
What my workaround does, is, it replaces ä,ü,ö and ß with ae,ue,oe and ss in UTF-8 strings and afterwards converts from ISO-8859-15 to UTF-8. If the string was already UTF-8 or is not ISO-8859 it doesnt matter, since the critical characters were already replaced.
superfecta.class.php
line 191: $callerid = strtr($callerid, array(“ü” => “ue”, “ö” => “oe”, “ä” => “ae”, “Ü” => “Ue”, “Ö” => “Oe”, “Ä” => “Ae”, “ß” => “ss”));
line 205: $callerid = iconv(‘ISO-8859-15//TRANSLIT’, ‘UTF-8’, $callerid);
Thats just a workaround…
A real fix would do the conversion lookup-source-specific…aleady within the template.