A very good quality Duemilanove clone board I purchased doesn't mention Arduino on the board at all. I bought it from a UK supplier, but it came from here:
http://www.dfrobot.com/index.php?route=product/product&product_id=49
It clearly is a clone, from the description.
I got a DFRduino and the external power voltage regulator does not work correctly (everything else works ok). Maybe it is a DFRduino clone.