Closed loop stepper motors

Hi, Is anybody using closed loop stepper motors on the LongMill?? My LongMill 3030 was finally fired up for the first time today and the X-axis apparently missed some steps so the work piece was effectively shifted to the left and the job ruined. It occurred to me that a closed loop stepper motor would probably prevent such a problem and I wondered if anyone in the LongMill community has tried using them?