I do not have an Xcarve myself as I have built my own (my thread My DIY-carve )
So I have gone through many of the typical errors / failures one can encounter (have some not encountered yet I am sure!)
It is a learning experience and with any hobby machine one need to expect tweaking. Some will tweak for a longer time than others, tweaking = getting rid of all the small issues that prevent smooth operation 
Happy carving! 