Have tested with and without the patch from
GLASSFISH-20449. Simple test case:
HttpURLConnection uc = (HttpURLConnection) new URL("http://localhost:8080/WebApplication3/NewServlet").openConnection();
OutputStream os = uc.getOutputStream();
What happens is that normally the servlet will print 6 to the console - but if you add an EJB session bean to the app it prints 0. Trying to read from the servlet input stream causes EOFException.
GLASSFISH-20449 is about taglibs and session beans, and this seems similar - however the patch I tried for the taglib bug did not fix this problem.