Static checker fails on correct code

Sample project to reproduce attached

Static checker fails compiling the following code

import groovy.transform.CompileStatic

import javax.servlet.ServletContext
import javax.servlet.ServletRegistration

/**

 * author: Richard Vowles - http://gplus.to/RichardVowles
 */
@CompileStatic
class ServletExample {

  public void myMethod(ServletContext ctx) {
    ctx.getServletRegistrations().each { String name, ServletRegistration sr ->
      println name
    }

  }
}

with the message
Groovyc: [Static type checking] - Cannot call org.codehaus.groovy.runtime.DefaultGroovyMethods#each(java.util.Map <java.lang.String, java.lang.Object extends javax.servlet.ServletRegistration>, groovy.lang.Closure) with arguments [java.util.Map <java.lang.String, java.lang.Object extends javax.servlet.ServletRegistration>, groovy.lang.Closure]