tried moving the IDE port from Master to Slave position
How did you do this?
One thing you could try is clearing the BIOS by either jumping the pins or removing the battery for a few minutes, this will reset anything you've done in the BIOS.

If you haven't done so yet, check where the jumper is on the back of the LG drive. If set to slave and it's the only drive in the computer, then BIOS won't see it. Also, try a different cable.