System Administrator Liggy, has been busy at his keyboard once again and has provided the always online NEC Forum crowd a new special firmware to try. Among other things, this brings bitsetting support for DVD+R, DVD+R DL and DVD+RW to your drive. The comment below was the first in what became a very active thread so even though it is a beta, to be used at your own risk, everyone seems to be having success with this firmware. In fact some there think it is the best one out at the moment.

I just wanted to know if anyone is interested in testing a patched NEC 2.18 firmware including bitsetting support for single layer DVD+R and DVD+RW?   I used the bitsetting code from MadDog 2.fa and integrated it into the 2.18 firmware. The firmware is completely untested and may give unpredictable results, but I hope it works as expected.   Riplock is removed, RPC1 included and the firmware can be downloaded here. If you don't have Binflash or any other flasher, you can use this version with integrated flasher.   Any results (whether positive or negative) are highly appreciated.

To use Binflash GUI version shown above to flash your NEC 3500 drive, simply download the firmware RAR file and unpack it to a folder of your choice. Then invoke the Binflash program and select the Flash button. Navigate to the folder with the unpacked firmware, find the BIN file, confirm the above dialog box and once completed, reboot.

Source: CD Freaks NEC Forum