There is no 'bitsetting' option in Nero CD-DVDSpeed.
Yet, from the NEC Big FAQ:
[I]"Q: How do I set booktype DVD-ROM?
A: Some firmwares support AUTO bitsetting, in this case all +R +RW media will have itâ€™s booktype set as DVD-ROM. Other firmwares allow you to manually set booktype. As a general rule, you should set all supported +R media to booktype DVD-ROM. You can do this with Binflash or the NEC WinBtype utility, newer versions of Nero CD-DVD Speed also support this feature. In each case the booktype setting is remembered in the firmware and you will only need to set this once, unless you wish to change the booktype again.
In the case of the 1300 and 2500 series of drives Booktype DVD-ROM for +RW worked by using some firmware supporting RICOH type bitsetting. This doesnâ€™t work on the 3500 series.
35xx series update
Originally Posted by GlamRocker
First set +RW to DVD-ROM then get a brand new +RW disc (not a used one, erasing and formating is useless for first setting the booktype), pop it in the drive then open any burning tool of your choice and burn the disc, it should be set at DVD-ROM.
Then get a used +RW and erase or format it and it also should be changed from +RW to DVD-ROM. [/I]
So, apparently, the stock NEC firmware will not let you set the booktype, but the hacked will? In any case, that option does exist in DC/DVD Speed. I just wondered why it appeared disabled on my system. I'll try it with a burned DVD and see what I can see.