I don't believe it's a Spring 3.0.5 problem (just tried the showcase in Spring 3.0.5 to be sure).
The encoding is done on Facebook's side after the POST. Even with my working showcase sample, if I trace the POST request, the response comes back as HTTP 302 with the Location header set to "https://graph.facebook.com/oauth/authorize?client_id=0b754d95f9c9899b0d6c4454b6f2dd e7&redirect_uri=http%3A%2F%2Flocalhost%3A8080%2Fsp ring-social-showcase%2Fconnect%2Ffacebook&response_type=code&s cope=publish_stream%2Coffline_access" (notice the encoding in the redirect URI).
I'm wondering if this has less to do with how you've configured Spring Social in your app and more to do with how you've registered your app with Facebook. In your application's settings on Facebook, what is the Site URL set to? If it's a relative URL (or possibly if it's empty), then that may be your problem.
Last edited by habuma; Jun 8th, 2011 at 02:56 PM.
Spring Social Project Lead