This is a bit of a weird one, but I started a print earlier, and after about 20 mins I came back to hear no real noises (other than the fan), when I looked in to the build area, I saw that X/Y had just stopped, and the head was sat in the same place, extruding away merrily.. The display was indicating it was mid-print with the progress and time remaining still showing, and I could abort the print, at which point the bed/head all moved back as normal after aborting. Here's the pics.. After