Sounds like much of you have had 'Benign paroxysmal positional vertigo'. Often caused by a blow to the head that knocks calcium deposits (stones) out from soft tissue into the fluids of the ear canal.

http://en.wikipedia.org/wiki/Benign_...tional_vertigo

There is a simple test you can do yourself.

http://www.dizziness-and-balance.com...bppv/bppv.html

The Epley Maneuver works as a fix for many people.

http://www.youtube.com/watch?v=pa6t-Bpg494

The Epley Maneuver moves the stones into a spot that they cause less problem and where they will be absorbed back into soft tissue.