Replying again to myself just in case somebody else stumbles over this. I've modified the Webservice client to pass the correct encoding (not UTF-8 but e.g. KOI8-R) to the Call object of Axis (CHARACTER_SET_ENCODING). That way I can transfer the correctly encoded characters to the server (I checked this with tcpmon). But then I get error messages about other illegal characters like 0x1 once the content is parsed on the server side :evil:
Does anybody have a working example to store somewhat "exotic" characters (chinese, kyrilic, whatever) as property in Alfresco?