Everyone experiences sleep paralysis, its natural to keep your body from moving while you are dreaming. It can be a bit scary if you happen to be awake for it, which happens to everyone occaisonally, even people who don't try to LD. At least, everyone I've ever spoken to has had at least a few experiences that could be attributed to it.

I personally sleep on my side and although from everything I've read, SP is less common among side sleepers it certainly isn't impossible Just a few months ago I woke up thinking someone was in the room with me and hearing strange noises which continued everytime I started to drift off. It was really creepy and freaked me out.

Of course, with the WILD techniques, the whole goal is to be conscious during SP. Personally I have never had anything really "scary" happen to me while WILD'ing (knock on wood). I mainly get the sensations of SP - falling or spinning in my case. Those are extremely fun, like riding on a roller coaster! I have never heard weird noises or seen demons or any of the other stuff people report though. I think everyone is different