Hi Ceki and all,
I figured the problem out so there's no need to answer my previous email.
FYI:
What was missing is the CallerData object that apparently needs to be defined....
Here is the code: (in addition to the code in previous message)
CallerData callerData= new CallerData("somefilename.java", "foo", "methodFoo", 123);
CallerData[] cda = new CallerData[1];
cda[0] = callerData;
//then I added the callerData to the event...
event.setCallerInformation(cda);
This did the trick.
I'm happy ;-)
Gregory