I use a portable LG DVD ROM drive (USB) and do not have this problem. Do you have two USB ports, one for power and one for the connection? Its possible the revo USB can't support the power requirements for the drive? But then again, you installed with it.
So have you looked at some options, like a possible driver update on that system? Do you have any CD cloning/burning/imaging software that might be conflicting with the device?
Are you using a connection method that is different from the main computer? Does the disc tray open when the device is powered on when connected to the Revo?
The USB controller on the Revo is likely not recognizing the device. You could look at updates for this computer in the form of chipset updates from the official website. And, possibly, look for a firmware update from Lite-On through their website?
This is a tough one for sure.