I have no idea if this will apply to you or not, but, I looked into replacing a CD-ROM drive on a friends Toshiba, and I found out that the replacment drive either needed to be set in the firmware to either Master or Slave (can't remember which), or, it needed to have pins on it shorted.
Keep in mind the notebook opticals aren't like desktop opticals, there's no jumper you just put on...the shorting is done either by solder or soldering a wire to the correct pins to force Master or Slave operation.
Just pointing this out as it could be something you run into...
Chuck