The new bows with the all fiberglass limbs are much more sensitive to temperature changes then the old laminated limbs. As far as something moving, when you get it shooting good (paper test) write down all your measurements after taking them with a good bow square such as nocking point height, loop top and bottom, upper and lower tiller measurements. It's easy to catch a problem then.
And use a peep sight in the string (and take the measurement on that also)...