A couple users reported problems since Groovy 2.0.2 with the GroovyServlet:
When using Gaelyk on Google App Engine, they noticed that the first hit for a certain groovlet would run fine, while all subsequent calls would fail.
This problem started appearing after the changes operated on
GROOVY-5125 which fixed an issue when using scripts stored in a JAR with GroovyScriptEngine.
This problem can be fixed by amending AbstractHttpServlet.