I have been searching different threads since yesterday and figured why not start my own. I have a Macbook Pro 10.5.3 2.16 GHz with 2GB 667 MHz DDR2 SDRAM. The problem that I am having is that neither of the 2 usb ports nor the 400 firewire port is recognizing any of my external hard drives. I recently bought a 320 GB Verbatim Firewire/USB Drive and it is not mounting or showing up in the System Profiler, Disk Utility, or Drive Genius. It is formatted for Mac and works fine on my other Mackbook. I am having the same problem with other external drives on my Macbook Pro and I have tried using different cables. All of my drives do not use external power; they are powered via USB or Firewire. The lights on the drives are coming on when plugged in but the disk never mounts anywhere. Thank you guys in advance for any help. It is much appreciated.