Error in migration a application of the tomcat 5.0.28 to Tomcat 5.5

Hi folks, I have a application in tomcat 5.0 and when I migration to tomcat 5.5 I have the erro in generation jasper reports: Servlet.service() for servlet action threw exception java.lang.NoSuchMethodError: org.eclipse.jdt.internal.compiler.env.NameEnvironmentAnswer

How set a default context

Hi people, I need your help, I install the tomcat 5.5.17 in my sever, and I have two context in webapps: /portal and /intranet, when I start the tomcat the two application run ok, but I need set the default context ( http://localhost:8080) that call the /portal context, Someone can help me? in