You're confusing string theory with something else, or perhaps the theory that you saw was mistaken. I could try to go into an in-depth explanation, but I would likely confuse the issue instead of clarifying.

I'd suggest wikipedia's entry on string theory (and all of the links involved). String theory is definitely not for the faint of heart, but the study is well worth the effort.

I have read of this theory before. It was a slightly different version than the one you have outlined here. It states that the universes are membranes within another space of infinite size and five dimensions. these membranes are constantly floating around inside of this space. if two of these membranes collide then it creates kinetic energy along the entire membrane and the vibrations of the kinetic energy form sub-atomic matter such as quarks. This makes a membrane imprinting itself onto another unnecessary to create the matter we see today in our universe. this version of the theory I think solves the problem of the membranes losing energy once they imprint onto another membrane because they don't have to imprint.

I suddenly recall that acc. to Hawking those particles enterered and then speed up!? Again no explanation just that given what we are now that must have happened. energy becoming instant matter, time=space created.
Gravity then created.
I'll just use this space as my exterior memory...

I always understood that branes could be any and everywhere just pop up from nowhere...as it were :)
Not necessarily creating a violent big bang but just little snaps any and etc. etc.

On http://en.wikipedia.org/wiki/Hawking radiation
I found sufficient information to get me out of the post-modern middle ages of my knowledge.
Planck mass and lenght are closely related to our existence i.e. for the laws of Newton to be still applicable, and the age of our universe, giving a black hole the mass of 0.8 earth.

M-theory: strings grow in branes even upto the size of an universe, to vibrate in six dimensions + time.
0-brane: zero-dimenional point.

1-brane: 1-dimensional particle; string open or closed.
string theory:
2-brane: 2-dimensional 'membrane' non-perturbative theory.
Non-perturbation theory, i.e. a static number of dimensions include:P-brane
M-theory
brane-cosmology
P-brane: sweeps out a (p+1) dimensional worldvolume as it propagates through spacetime.
Black-brane:black hole
Some approximations of black branes might lead to entropy consistent with energy from E=mc2
Black P-brane: solution for equations that generalize a black hole solution, extends translationally symmetric, in additional spatial dimensions.
D-branes
Dn-branes: form in type IIA string theory.
odd Dp-brane: type IIB string theory
M1-super: magnetic dual M5 brane.
F-string: it's magnetic dual NS5-brane/non-perturbation theory.