According to my knowledge it is possible to break the lock bits and copy programe. I heard some people are doing this type of bussiness. Dallas is more secure then atmel.
Another thing I want to add is that some people duplicate your product I mean they actully programe by them self and developed same product if they see big market in that particular product. In your case it may be possible that they actually coded and made same product.
There is a very big loop hole in Atmels security bits.

Bye