I have a 1620 also, and as I recall, all disk types are set to ROM out of the box. (DVDD does this "failure" message on my drive also.) However, if you want to check, the simplest thing would be for you to download the BenQ Qsuite program, which contains a Booktype setting utility, and will also tell you the current settings of your drive.
And proceed to the Download Center for your product, choosing "Software" as the download type.
If you are still unsure if your BenQ is burning disks as ROM, just do a test burn, and use CD Speed or similar info program to tell you what booktype the burned disk is.