Hi. Got a Tascam US-1641 audio interface which my MB pro has trouble detecting. Sometimes it's absolutely fine and will work all day, other (most) times it flicks from on to off again in the Tascam control panel. Takes ages looking for it and freezes the mac in the process, then fails to load. Tried different orders of booting up - mac first or unit first, and have downloaded version 2 driver. Using usb2 cable. Couldn't seem to download firmware from Tascam site- mac crashes every time! Any help very gratefully received!