Paul Bakaus

David is correct, digital projectors refresh even more often than 48 times to reduce flicker, common standard is 72, often up to 96. Like he also said, more refreshes doesn't improve motion, it just makes the black phase between frames shorter to reduce the fusion flicker threshold (if the screen is black for > 16ms, we perceive it as flicker, and our peripheral vision is even more unforgiving, so a a high valueto reduce makes sense). So sadly not an answer to what you perceived, but thought it might be relevant/interesting anyway. Shameless plug, a more detailed explanation about movie projectors (and the various other display types) can be found in my guide here: http://paulbakaus.com/tutorials/performance/the-illusion-of-motion/.