Then if to speak of CD-RW's?
I just read in firmware readme for NEC ND-3500AG next.
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)
On other forum i read that 
	
	
		
		
			OEM: May be "rebadged" for other companies. The rebadging might include changes to the faceplate, and/or the firmware. OEM drives are often sold in bulk (large quantities) to companies like Teac, Asus, Dell, Sony (for their desktop computers)
		
		
	 
Maybe this is reason why they dont recomend to flash it.