If any of you have had a problem with an external hard drive "pausing" durring transfers, I seem to have found a fix... not really a fix, a reversion.
Turns out there is a problem with the USB 2.0 driver that is causing it.
You have to revert all of your USB ports back to 1.1. It's really annoying, but fixes the pauses. Unfortunately it limits the speed to old 1.1 speed which really slows things down.
I wonder if there is a USB->SATA cable... going on the hunt...