Is your device an IDE internal one or is it the USB external version ? As far as I see, your device is connected via the ide-scsi driver, so you must be using a 2.4 kernel.

Maybe try this: Look at the DMA status for your device. To do this, identify the _real_ IDE device name, and type:

hdparm -d /dev/hdXX (where hdXX is your device name)

If DMA is not enable, then enable it. It is a nice option to also pass -X66 to enable UDMA, that is not set by default with 2.4 kernels.