Anyone able to get this to work? I'm having the same problem, and can't even get the sample I downloaded from https://community.jboss.org/wiki/JBossAS7SecurityCustomLoginModules to work. Like you, I'm getting:
13:52:47,103 TRACE [org.jboss.modules] (Remoting "1001467" task-2) Finding class custom.MyLoginModule from Module "org.jboss.as.remoting:main" from local module loader @50988 (roots: /opt/jboss-as-7.1.1.Final/modules)
13:52:47,104 TRACE [org.jboss.modules] (Remoting "1001467" task-2) Class custom.MyLoginModule not found from Module "org.jboss.as.remoting:main" from local module loader @50988 (roots: /opt/jboss-as-7.1.1.Final/modules)