I downloaded Firmware v2.18 from nec.de since the latest version on US site is 2.17 and readme say.
Firmwareupdate ND-3500A(G) - Important Information:
[F/W revision Brands]
2.18 (WIN) - 08-Nov-2004
You will find information for firmware 2.18 changes on our FAQ: http://www.de.nec.de
-> Support and Service -> Technical questions -> Optical storage -> DVD / DVD Writer
-this Update works only with NEC ND-3500A(G) retail/ bulk, not with OEM releases.
(OEM means part of a full PC package or external USB/FireWire variant of this burner)
>For OEM products contact your dealer, distributior or manufacturer of PC-/ USB-package.
-You can only update from official Firmwareversion 2.16.
How you think its just marketing or there is some reason for that?
Also when you flash firmware its completely replaces previous version right?