Axis skipping movement (1 reply)

So this is a rather weird problem for me. I have all of my axises working and calibrated. They move manually and during a print; except sometimes. During a print, the x-axis will miss an entire g-code command and instead stall with a high pitched whine. The print then continues and the x-axis begins moving again except now the print is shifted off. I'm not really sure what could be causing this because I cannot replicate it manually and it happens at random parts during the print. This will happen with the y-axis as well but not nearly as often.

Any idea of what could be causing this?
Also, how can I track my print line by line so I can see which lines specifically cause that problem.

Mac OSX, Ramps 1.4, Sprinter, Slic3r, Repetier-Host.