Sonatype Nexus on JBoss

After our main Nexus broke through an updat from 1.3.6 to 1.5.0 I had to create a temporary Nexus.
I already had a working JBoss (5.1.0.GA) install on my machine and wanted to deploy the nexus webapp there.
After installing and trying to acces it I got:

javax.servlet.ServletException: non-HTTP request for response …

After digging around for a while I discovered a servlet-api.jar inside the nexus.war.
Removed it and now everything is working finde.
Thought this one was worth sharing.