(forgive me, I've been gone a while, and haven't read through this whole thread, so if this has been brought up already I apologize)

Anyone that's ever said this to me has been watching Blu-Rays on a TV with a refresh rate of 120 or 240Hz enabled. Sometimes it's called "smooth motion" or something similar.

This essentially "adds" fake frames in between the real frames, which creates very unnatural, "fake"-looking motion.

The solution is simple - turn off the 120/240Hz setting. If at all possible (i.e., if your player and HDTV support it), play your Blu-Rays at true 24fps (24Hz), as that's how they were shot. If not, standard 60Hz or 50Hz (depending on where you are) will look just fine, especially since that's what SDTV's are, so you're probably used to that refresh rate already.