You don't mention the username and password you are using. For an
out-of-the-box geronimo server the deployment username and password are
username=system and password=manager. The following should work for you:
java -jar bin/deployer.jar --install --user system --manager --module openejb-itests-beans2.jar
FYI, M3 has a number of known problems. M4 is due out real-soon-now...