Single DVDRW drive seen as two in device manager and is VERY slow!

I hope this is in the right place:

A while ago my DVDRW drive died in my 1 year and 2 week old Dell Inspiron 9400, (just out of warranty). The Dell people kindly sent me a replacement drive which I installed very easily, one screw and that was it!



Anyway since then the DVDRW drive is reading VERY slowly taking 10 or more minutes to transfer fills that would normally move in a minute or two.



When I decided to uninstall and reinstall it I found in Device Manager that the DVD/CD ROM drives was showing:



LH3401K FLK5491 SCSI Cd Rom Device

TSST corp DVD+-RW TS-L632H



Now I know I have only one DVD drive installed but I can't seem to tell the laptop. I figured there is no SCSI device so I have uninstalled that only to have it reinstall itself, at present it is disabled. I have upgraded the firmware and driver. The BIOS recognizes the DVDRW and the diagnostic tests don't show up any problem so I am a bit stuck.



My problems are:



1) How do I get device manager to recognize only the one drive, (and why has it been seeing two?)?



2) Why is the DVDRW drive so slow at reading, (if it was a conflict between the 'two' drives then surely by disabling one it should have been resolved?)?



Please help as I haven't much hair left to tear out!



DELL INSPIRON 9400

WINDOWS XP SP2 (FULL UPDATES)



Thanks in advance.