If Liferay is running in a JBoss container,
you should not copy the JSF-impl.jar into the WAR. JBoss itself manages that.
Your actual problem sounds like a different situation, however. If you have an el-impl.jar file in your WAR, remove that. Neither JBoss nor Tomcat6 needs that, and it will interfere with the
Tomcat internal copy of el-impl.jar
The secret of how to be miserable is to constantly expect things are going to happen the way that they are "supposed" to happen.
You can have faith, which carries the understanding that you may be disappointed. Then there's being a willfully-blind idiot, which virtually guarantees it.