Is there a difference between Acetal and Delrin?

http://bit.ly/ZD44q5
Is there a difference between Acetal and Delrin?
I work with plastics and I was wondering,is there a difference between Acetal and Delrin? They look the same, or are they really different types of plastic? The supplier say they are not the same. They say that Delrin is a Homopolymer and Acetal is a Copolymer in the Acetal family.