xdj aero with traktor stops working after 1,5-2 hour

the xdj aero soundcard stops working on 1 chanel after 1,5-2 hour , sound tru usb dont work ,  the only way is to restart the xdj aero with the powerkable

in the beginning  i also had sometimes that the sound from the midicontroler did sound very bad after played 2-3 hour , from traktor and from usb and the solution was to restart the xdjaero tru by take out the powercable, thats happening 3 times i live gigs and its a big problem, now a have a extra mixer with traktor on ipad as backup

mac book pro 4 years old 8 gig memory with snow leopard , latest traktor that runs for snowleopard , i have reinstall the mac os x snow leopard and the error i still there !

any solution or feedback that i could check ??