website ...victim of doppelganger

Advert test
Website used to produce results on first Google search page for several keywords related to Irish Cottages but of late I have fallen below the radar. Frustrating.. and I assumed it was Panda or Penguin or some such. Now I find that parts of my site have been replicated in South Korean forum page complete with images and all links back to my site!! Any advice gratefully received. Do you think it is jealous competitors practising negative SEO or could it be a simple case of some Korean kid at play. Thanks in advance.
Also, I discovered that a Galway based website company had stolen several paragraphs from one of my pages. I managed to get a link and acknowledgement from him but should I have demanded payment?
If you think you are loosing visitors to the page in Galway, by all means ask them to remove it. I don't know about getting payment.

Not much you can do about site in Korea. Check that hot linking your images is prevented by your setup, at the very least it might save you some bandwidth.