Sony DRU-700A DVD drive detected as Sony DRU-530A

After I install my Sony DRU-700A (indicated in drive metal case that it is a Sony DRU-700A and front panel has a double-layer sticker on it) in Pentium III with Win XP Professional SP1 OS, the Sony DRU-700A is detected as Sony DRU-530A with firewire 1h (from Nero DriveInfo). Is there any way to confirm whether this drive hardware-wise is a DRU-530A or DRU-700A? Do I have the wrong model? What is the difference between DRU-530A and DRU-700A models that I can tell visually inside the drive metallic case.
Thanks in advance,