Use of ProfileTokenCredential

Hi all, 

I am trying to use "ProfileTokencredentials" to swap user id's.  When I try to 
do the swap i get an exception "Request is not supported". Am sure I am missing 
something here...can someone point out what is it that I am missing. 

Here is my code snippet.

                        try
                        {
                                pt.setSystem(cmdConn);
                                pt.setTimeoutInterval(3600);
                                
pt.setTokenType(ProfileTokenCredential.TYPE_SINGLE_USE);
                                pt.setTokenExtended("BALN01","srinivas1");
                cr = pt.swap(true);
                        }catch(Exception e)
                        {
                                e.printStackTrace();
                        }       
Thanks
Narsi