Watch out folks in 1024. When you turn on J2EE from the Project settings, you will be asked to set it up by finding the Servlet file. if you choose a library it will tell you it can't find the class file, if you however just use a jar file, everything is OK. So use Jar not Module Library or anything.
I've filed a bug for this:
I'd like to suggest that as we find bugs we post the links in here so we all know what they are.