bump

Just put together a new bike from bikes direct and got instructions for adjusting derailleurs. Everything looks fine on the Fuji so its something that's not immediately visible on the outside. Does anyone know what could cause this noise and slipage? Im not sure I want to tear up the back wheel to tinker with it without knowing what im looking for.

edit: I pulled the rear wheel off, held it and turned the cassette with my hand. It looks like there's a 1-2mm slip. Anyone know how to fix this? Should I even try to do this myself or should I take it to the shop? I've got free lifetime adjustments and only bought the thing 1 month ago.