It is an amazing coincidence that you bring this up right now. Last night I started a graduate course where we needed to install and use Tomcat. I had an old Tomcat install lying around but wanted to start fresh, since I'll be sharing it with a few team members, and wanted to get a current version (I downloaded 4.1.18 I think.) And I ran into a similar problem, being unable to run JSP's.

If you can't compile JSP's, chances are you don't have "tools.jar" (from the JDK lib directory) in your classpath. I tried many different methods for getting the directory where it's located into my classpath, but eventually I ended up just copying tools.jar from the JDK lib directory into <Tomcat Root>/common/lib, since any JAR files in that directory are automatically loaded into the classpath on startup.

Once I did this, I was able to run JSP's, and start it as a service. Your mileage may vary, but I was thinking maybe in some kind of cosmic coincidence it's the same problem.