You should upgrade to the Tamino Client that comes with Tamino 2.3.1. This has some fixes for encodings. If this doesn’t fix it report a bug.
Changing the acceptCharset property only changes the way that the Client talks to Tamino. The Client works in 16 bit Unicode and Tamino works in Unicode also. The Client by default uses UTF-8 to communicate - If you change acceptCharset to another cahrset then the Client will ask for its responses in this charset. However the parser/DOM in the client will parse the input and convert into 16 bit unicode - So you will only see a difference if the Client or Tamino doesn’t know the encoding you specified - then you get nothing 
“So what is it for?” you may well ask. It is a throwback to early Tamino versions when the interface was somewhat different and you could do some interesting workarounds with this feature.
I could repeat the whole story again for setEncoding(), but I’m sure you’ve got the idea by now.
regards
Nigel Hutchison
#API-Management#webMethods-Tamino-XML-Server-APIs#webMethods