I don't think whywhywhy is confused as to what they have. Several other members seem to have never heard of oriental poppies, which is strange to me - I didn't think they were unusual!
Actually, just had another idea. If you have been top-dressing for several years, perhaps they have become buried too deeply? I still wouldn't try to dig them up (they have deep, fragile taproots), but maybe scrape some of the surface off while they are dormant.
