[Dyerryjex]

No, the falling sensation is a normal part of falling asleep and indeed could be associated with separation or dislocation, but it could also be physical (and normal.) I believe it's called a Myoclonic Jerk and if it's not on the ADPedia (in my sig) it should be.
What meditation does is make you more aware of things that happen and go unnoticed. This is what 'opening up awareness' really means, and nothing to do with holes in defenses or anything else like that. Unfortunately (or fortunately, for survival purposes) a lot of stuff in life goes unnoticed, and that's why meditative and introspective work makes you see more of what is there. This makes people think that the work made the things be there, but it didn't- it just made people notice what was there anyway.
Kind of like a microscope, for example- germs (originally called 'little beasties' by Lewwenhoek (I prob. misspelled that horribly)) they're there and they can make you sick, but looking in the microscope just shows you they really are there.
To avoid being unnecessarily scared about things that are energy and consciousness related, I suggest you read the thread "Your first conscious projection", in the New Members section (there may be a link here, I'm not sure) which describes a lot of stuff you may experience that is energetically related- but startling or scary to someone who has not much experience in the discipline.
Ta for now,
CF.