From Slashdot news: Even if NEC tells you its impossible, German netzine Golem is reporting hackers have created an updated, unofficial version of the firmware providing DVD+DL (Double Layer) capabilities. Currently model 2100A and 2500A are patchable, more will hopefully follow soon.
If you happen to have any of these drives perhaps will want to void your warranty and give us a hint whether the firmware really works? ;).