I'm having a similar problem with the same drive, ND-3550A, in a new system. It will recognize the drive as a DVD-RW but as soon as I put a blank DVD in there it switches the description to CD Drive and when I try to open it an error comes up "E:\ is not accessible. Incorrect function". Now the thing is I installed my old LG DVD-RAM in there and it's doing the same thing but it was working fine in my old system a couple weeks ago. Now the only thing I can think of is that this time around I'm running SP2 and Nero 7 and somewhere there's a conflict. Neros Info Tool recognizes everything correctly and I can burn DVD's within Nero.