--- a/langtools/src/share/classes/com/sun/tools/javac/code/Symbol.java	Tue Mar 06 16:48:29 2012 +0000
+++ b/langtools/src/share/classes/com/sun/tools/javac/code/Symbol.java	Tue Mar 06 16:50:32 2012 +0000
@@ -1235,7 +1235,7 @@
             // if origin is derived from a raw type, we might have missed
             // an implementation because we do not know enough about instantiations.
             // in this case continue with the supertype as origin.
-            if (types.isDerivedRaw(origin.type))
+            if (types.isDerivedRaw(origin.type) && !origin.isInterface())
                 return implementation(types.supertype(origin.type).tsym, types, checkResult);
             else
                 return null;