Only standard-ASCII characters work as payload-data within XML-RPC requests. If there are national chars (eg an umlaut like ' ö ä ü ß'... ) this characters generate Errors.

There are also problems transferring UTF8-Chars from the 'Backend' to the 'Frontend'.

Find attached my test .lzx/.java

Steps to solve the problems:
1. The provided xmlrpc-1.2-b1.jar lib doesn't handle UTF-8 properly. An update to Version >= 2.0 is needed. Just replacing the lib worked for me...
2. The Flash Plugin uses UTF-8 encoding, but dosn't set the HTTP-Headers properly. The attached patch "utf8-xmlrpc.js.patch" to lps/components/rpc/library/xmlrpc.js fixes this issue.
3. The XMLRPCCompiler.java uses Program.push() which defaults to "Cp1252"-encoding. Seems to originate from Flash-5 times.... The attached file XMLRPC-UTF8-compiler.patch addresses this issue.

Now UTF-8 data is working for me in both directions...