Compiling @Immutable classes in IDEA 8.1.3 and 9.1.

Would be great to have some idea of what's happening with the following compilation issues

1) Here's what I get when compiling immutable classes in 8.1.3

Eg,

@Immutable final class ImmutableExample {
  int a
  int b
  int getSum(){a+b}
}

and another with a field referencing the former:

@Immutable final class ImmutableCompositeEg {
  ImmutableExample example
  int c
  int getSum(){example.sum+c }
}
I think this should be legal in Groovy?  However, when I run

def eg= new ImmutableExample(a: 2, b:3)
def egComposit = new ImmutableCompositeEg(c: 4, example: eg)

I get the error.

"Caught: groovy.lang.MissingMethodException: No signature of method: static org.codehaus.groovy.transform.ImmutableASTTransformation.checkImmutable() is applicable for argument types: (java.lang.String, java.lang.String, designgui.ImmutableExample) values: [designgui.ImmutableCompositeEg, example, designgui.ImmutableExample(a:2, b:3)]
at designgui.ImmutableCompositeEg.<init>(ImmutableCompositeEg.groovy)
at Explore.run(Explore.groovy:14)


2). In 9.1, it is the same problem. Besides, when I rebuild the project I get the following errors

C:\Users\pcw\.IntelliJIdea9M1\system\compiler\optnew.OptNew8d7cbdbe\.generated\Groovy_to_java_source_code_generator\designgui.f53ada3a\production\designgui\ImmutableCompositeEg.java
    Error:Error:line (4)illegal combination of modifiers: public and private
ie, in the java code,

public final class ImmutableExample implements groovy.lang.GroovyObject {
  public private final int getSum() {
    return 0;
  }

Any feedback would be appreciated

Message was edited by: Oleg Volkov Oops, forgot the builds: 8.1.3 is #9886 and 9.1 is # 10372