I got a seagate freeagent pro usb/firewire external HD recently, and just yesterday got it hooked up to my home setup (the HD connects to a cinema display with firewire, and the display connects to my macbook). It seemed fine when I used it with just the macbook, but now the new HD is causing terrible slowdowns. Applications are taking 4-5x as long to launch as when the HD is off. Disk utility says both the internal macbook HD and the seagate are fine. Suggestions?