Hi dodonohoe,
sorry you're experiencing these issues. There are several things you can try here. Firstly try your usb buffer in the setup screen of ITCH. Try raising this up. Ideally you want to have it as low as you can without dropouts.
Also run through these optimization tips. Many laptops aren't designed for audio use and may require some tweaking. See here for details:
serato.com
Also for a more detailed rundown check here:
blog.dubspot.com
Make sure you aren't using an unpowered usb hub, connect your Xone:DX directly to your computer, and try not to run any other background tasks/programs while using ITCH.
Let me know how you go with those.
Mathew