If my high school and college German hasn't failed me, I think that what you are saying is that you are experiencing pauses during JBoss AS startup. Here is a prior discussion on that topic (the poster was using 3.2.6 but the general debugging guidelines still apply to 5.1.0):
https://community.jboss.org/thread/148705
The key is taking a thread dump during the pause, looking at the threads to see what they are doing or waiting on, and fixing that. Most likely, it is an issue with network access.
Also, are you behind a firewall that would prevent internet access on certain ports?