If it is the FREECOM_DVD+/-RW16B9 model (NEC 3500 rebrand)
I'd favour the Official update
http://www.freecom.com/firmware.asp?form1=true&form2=true&serie=12600&Manufactures=12600 (select internal)
As that appears to return a ZIP file with an EXE installer - yes, unpacks a single installer that runs in Windows - follow the instuctions and be sure you're aiming it at the right drive!
What does the drive call itself on the system, and what firmware does it currently have?
The firmware version follows a fairly logical code, so far:
The first digit, so far, is 2
The ".n" varies with brand:
.0 is NEC OEM, .1 is NEC Retail (I may have those mixed up)
.2 is IODATA, .4 is Freecom, .7 and .C are TDK, .F is Mad dog.
The second digit does NOT imply later versions!
The 3rd digit is the actual version, though it can be skewed between brands - one brands "8" may be close to another's 7 or 9.
I would avoid using anything other than an official update, until you are certain the drive is not a "lemon", as unofficial tinkering would void the warranty!