Following the advice in http://code.google.com/p/google-web-toolkit/issues/detail?id=4220#c22 I also installed the latest WebKit build. Since I normally compile and run with Maven from the command line I simply added the following to my .bash_login:
New Features in the Latest Cloud Foundry: "We recently updated CloudFoundry.com. With this update, we introduced several exciting new features that pave the way for future development. I want to take this opportunity to describe and explain these features, as well as provide some background in how they came about. We are excited for you to try them out [...]"
Need to take a look at this as an avenue for hosting FB apps. FB -> Grails -> CloudFoundry might be considerable better than FB -> Grails -> AppEngine.
It turns out the deceptive exception can be thrown from an improperly formed Many-to-Many relationship declaration. I'm not going to take the time to document a correct declaration here but I was getting this misleading error message and was searching for an obvious problem with imports when it turned out to be the @ManyToMany annotation usage.
So inspired by this post and the discussion over in the gwt-dispatch group I have converted my application over from Guice to Spring. The only variance from the pgt blog post is that I am using net.customware.gwt.dispatch.server.spring.SpringStandardDispatchServlet in my web.xml. Other than that my action handlers are getting called as expected.
Linking to Matt Raible's notes on the GWT Maven plugin setup. I have basically the same findings.
I've added the maven-war-plugin for building a war for deployment. I've also had some problems since I'm not on Snow Leopard yet and there are JDK 1.6 issues with GWT and JDK 1.6 on Leopard.