When I have Presonus Studio Live plugged into firewire to my mac I cannot plug in my Helix to the USB. In logic pro. I have Logic audio settings set for the Presonus. Every time I plug in the helix, the helix freezes. I then have to restart my helix with the USB unplugged. I can use either, my Presonus or my Helix. Why can't they just be friends?