miniStack + Powerbook + Firewire

Here's my situtation:

I have been running low on disk space on my Powerbook for some time, and I finally bought an external hard drive. I went with the Newertechnologies miniStack and installed a Hitachi 7200 rpm 250 GB hard drive.

I set it up as a firewire drive, and thats when it happened. I started transferring large media files off of my Powerbook and onto the miniStack and this is what happened:

A progress bar would pop up as usual, and show the progress of the data. The drive would click, start to make a noise like it was starting to spin real fast and the data would move quicly in the progress bar. Then the drive would stop transferring data, make a clicking noise and start up again. This happens in a semi-regular interval until the file is done transferring.

When I configure the miniStack to USB, the data transfers at the slow USB pace that I have come to know and expect.

I don't know much about hard drives and firewire, but it seems to me as if the drive is to fast for the Firewire. What I mean by this is, it seems that the hard drive would send out data through the firewire at a fast pace, and then would stop so that the firewire could catch up, maybe creating some type of bottleneck of data. Like I said, I am not even sure if this is possible, but that's what is it seems like to me.

Also, I have heard that the firewire components that Apple installs in it's line of iBooks and Powerbooks are actually slower than those in desktops. I wonder if this could be manifesting itself now.

So, all ranting aside, I was curious if anyone had experienced anything similar to what I am experiencing right now, or can confirm or deny my theory about the firewire bottleneck, or the rumor about the Powerbook firewire being slower than those on the desktops.

I will try to connect my miniStack to a PowerMac at school and see if I get the same results.

Thanks