http://forums.java.net/jive/thread.jspa?threadID=12721&tstart=0

  There's a debug output left in XMLScanner.java in delta 1.1.3.1 :
1.1.3.1 protected void scanComment(XMLStringBuffer text)
1.1.3.1 throws IOException, XNIException {
1.1.3.1
1.1.3.1 //System.out.println( "XMLScanner#scanComment# In Scan Comment" );
1.1.3.1 // text
1.1.3.1 // REVISIT: handle invalid character, eof
1.1.3.1 text.clear();
1.1.3.1 while (fEntityScanner.scanData("--", text)) {
1.1.3.1 int c = fEntityScanner.peekChar();
1.1.3.1
1.1.3.1 System.out.println( "XMLScanner#scanComment#text.toString() == " + text.toString() );
1.1.3.1 System.out.println( "XMLScanner#scanComment#c == " + c );

It's still there in b77.