Topic: im using ufx as a live mixer problem. sometimes no sound.

Im using ufx as a live mixer with macbook pro usb connection using latest driver.
when i power up the ufx then connct usb to  the macbook,
sometimes  there is no sound from the main out to active speakers.
I see the sound coming into the unit and out from main out in the totalmix software, and all faders are all up on the right channels and outputs.
but no sound in the speakers.
I alway get sound  in the end
after turning on and off ufx and macbook couple of times and disconecting the usb cable.
am I doing something wrong ?.
Will this be better using firewire 400 to 800 cable?

Mvh who842