: I recently puchased a 30gb Lacie USB/Firewire Pocketdrive to replace/augment a generic 20gb USB/Firewire hard drive I had previously. I was disappointed that although both drives are based on 2.5" IDE "laptop" drives, the genric works fine with just USB supplied power while the much more expensive Lacie drive requires a supplemental power supply. The only major physical difference between the drives is the generic is a USB 1, and the Lacie a USB 2. Both drive work fine with Firewire supplied power. Anyone know why the Lacie won't work with just USB power?

The power limit for USB devices is 500 mA (and the device has to ask for it). Check if the LaCie works with an unpowered hub (which can only give 100 mA). If so you have the answer.