I bought a batch of Datawrite Greytops, FUJIFILM03, from UKDVDR and these work great on my NEC 3500 and Lite-On 1633S. However, a friend brought up what appeared to be the same disc (same colour/name/speed/type) and when burning to them, they failed in both the NEC and Lite-On!!
Checking the MID of these discs we found they were PRODISC F01 :Z so Datawrite definitely swap dyes and it's pot luck whether you get a good batch
To be fair to them, their Datawrite 8x +R that use PRODISC R03 dye burn at 12x on my NEC and gave a good Kprobe scan with my Lite-On :iagree:
So it's a gamble whether you get good burns or not depending on the 'current flavour' of dye they use