DVD Burner Loosing Power? (jumper placement)

Ok. I just recieved my HP 400i the other day and went to replace my external Iomega CD-R with this drive. However, when the HP unit is hooked up and the jumper is on Master (same as the Iomega), the unit looses power. If I move (or remove) the jumper to another postion, the unit has power but nothing happens when I connect it to the PC. If I reconect the Iomega, everything works properly

Strange stuff?!?