iPad air+Mixtrack pro 2 problem

Hi guys I just bought an iPad air with camera connection kit and a usb hub just to connect mixtrack pro 2...
I have a problem: When I connect mixtrack pro 2 to iPad via camera kit and usb hub sometimes Cross DJ recognize the MIDI controller sometimes no..
when it recognize it.. crashes after my first touch at the MIDI controller...and lost it
What can i do?
Thank you
I have a problem: When I connect mixtrack pro 2 to iPad via camera kit and usb hub sometimes Cross DJ recognize the MIDI controller sometimes no..
when it recognize it.. crashes after my first touch at the MIDI controller...and lost it
What can i do?
Thank you