The following test program throws an IllegalAccessException with gij,
but works with Sun Java.

~$ gij InvokeAnnotationMethod
Exception in thread "main" java.lang.IllegalAccessException
   at java.lang.reflect.Method.invoke(libgcj.so.90)
   at test.Helper.invoke(Helper.java:11)
   at InvokeAnnotationMethod.main(InvokeAnnotationMethod.java:11)

~$ java InvokeAnnotationMethod
~$ java -version
java version "1.6.0"
Java(TM) SE Runtime Environment (build 1.6.0-b105)
Java HotSpot(TM) 64-Bit Server VM (build 1.6.0-b105, mixed mode)

The odd thing is that if the test.Helper class below is moved up to
the default package, the program works. So there seems to be some
reflection bug.

Report forwarded from Debian:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=466538

------------------------- file InvokeAnnotationMethod.java ----------------
import java.lang.annotation.*;

import test.Helper;

public class InvokeAnnotationMethod
{
    public static void main(String[] args)
        throws Exception
    {
        Annotation ann = Inner.class.getAnnotation(Ann.class);
        new Helper().invoke(ann);
    }

    @Retention(RetentionPolicy.RUNTIME)
    public @interface Ann {
        public int param() default 0;
    }

    @Ann
    public class Inner
    {
    }
}
-------------------------------------------------------

------------------------- file test/Helper.java ----------------
package test;

import java.lang.reflect.Method;

public class Helper
{
    public void invoke(Object a)
        throws Exception
    {
        Method m = a.getClass().getMethod("param", new Class[0]);
        m.invoke(a, new Object[0]);
    }
}