If the data your application is using comes from a Microsoft application, there are some chances that the character set used to encode it is CP1252 (the same might apply to data received from an external xmlrpc server/client, but it is quite rare to find xmlrpc toolkits that encode to CP1252 instead of UTF8). It is a character set which is "almost" compatible with ISO 8859-1, but for a few extra characters.

PHP-XMLRPC only supports the ISO 8859-1 and UTF8 character sets. The net result of this situation is that those extra characters will not be properly encoded, and will be received at the other end of the XML-RPC transmission as "garbled data". Unfortunately the library cannot provide real support for CP1252 because of limitations in the PHP 4 xml parser. Luckily, we tried our best to support this character set anyway, and, since version 2.2.1, there is some form of support, left commented in the code.

To properly encode outgoing data that is natively in CP1252, you will have to uncomment all relative code in the file xmlrpc.inc (you can search for the string "1252"), then set $GLOBALS['xmlrpc_internalencoding']='CP1252'; Please note that all incoming data will then be fed to your application as UTF-8 to avoid any potential data loss.