IndexWriter RAMBufferSizeMB memory leak?

[it99]

If I use an IndexWriter and set the RAMBufferSizeMB to 16(default) or lower the memory is freed as expected and the memory of the process will level off to a nice level. If I set it higher  than 16 the memory does NOT look like it gets freed and the process continually leaks memory. Is there anything I need to do or is this a bug?

                IndexWriter iw = new IndexWriter(mission.getBaseDir(),
                                             new StandardAnalyzer(),
                                             true);
                iw.setRAMBufferSizeMB(32); //need a good way to determine how to set this
                iw.setUseCompoundFile(false);  

               //  looping ...
               iw.addDocument(doc);

              // finish looping
              iw.commit();
              iw.close();