[dnanian]

If the Mac isn't waking up, I can't think of any way to force it. But, since there is a "safe sleep" feature that kicks in when power is completely removed on a laptop, you might want to try removing the battery and then disconnecting the drive.

As far as using USB vs. FireWire, FireWire is generally preferred. But if this particular drive is giving you issues, USB might help.

Maybe you could also send me a system profiler report (XML, ZIPped) to the support address, with the drive and all other peripherals involved, attached. Might be something there.