TypedFML32 class does not have a Fprint32() method. It is something you could probably create using the class methods:
There is an XmlFmlCnv class with an FML32toXML() method. It returns a String object in an xml like format that is readable if you print it. Here is a usage:
Since the GWTDOMAIN thinks it is a NULL buffer there is nothing for it to print on the Tuxedo side. For this reason you should probably
turn on WTC debugging, dump everything to the WLS server log, and then see where/why the buffer was not sent.