I found a problem when compiling an idl generated from idl3 interface named with
suffix 'Operations'. The problem seems not exist in the trivial case:

module Test {
  interface TestOperations {
    void test();
  };
};

however, the definition described in idl which I put at
http://azalea.ics.agh.edu.pl/~cala/demo1.idl 
produces the following  error: 

[jacorb.idl] ERROR : demo1.idl, line:55(61): Undefined name:
demo1.Client._.demo1.DisplayOperations
Can't recover from previous error(s), giving up.
                void connect_to_server(in ::demo1::DisplayOperations

The IDL3 description demo1.idl3 may be found at
http://azalea.ics.agh.edu.pl/~cala/demo1.idl3

Problem seems to be in mapping to IDL as described in OMG IDL to Java Language
Mapping Specification at http://www.omg.org/cgi-bin/doc?formal/02-08-05 and at
pages 1-4 and 1-5.