A few years ago, i was really into astral projection and such, and i'd often get vibrations and i even managed to project once, but after that one time, i never was able to again, so i kind of fell out on that.
Now i'm interested again, and no matter what i try, binural beats and all, i can't manage to even get vibrations.
Is there any sort of explanation for what's happening? or is this just some sort of freak case?
One exit does not mean you can exit at will... Keep practicing patiently, and eventually you will progress...
It might be the methods you are using. Some have the ability to interfere with sleep (because sleep is needed to leave the body). Or, it could also be that you are simply not spending enough time. I don't want to give you an estimate on how long it takes, because then you might do it too short following my estimate.
This might help:
http://www.astralpulse.com/forums/viewtopic.php?p=193568&highlight=#193568
I have the same problem. It seems to come in spurts where I'm projecting every night and then it's followed by a dry spell.
I don't worry about it too much. I just move on to something else in the meantime.