This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
Tomcat5 has the EL implementation library built into the server. Your stacktrace indicates you're running a copy of WebSphere. Up until about WS6 or WS7, to use EL in WebSphere, you had to explicitly include the EL implementation library in your WAR.
Customer surveys are for companies who didn't pay proper attention to begin with.