Tamron has updated their 70-300mm f/4-5.6 lens with an internal motor so that it will work with the D40 and D40x. As if we don't have enough trouble with lens names, this one gets the acronym laden and cryptic AF 70-300mm f/4-5.6 Di LD Macro Model A17NII. Other than the internal motor, the only other specification I can see that changed is that it gained a slight bit of weight (probably due to all the extra ink in the lens' name ;~).