Hi bito94,
The scoring algorithm on the Official GMAT is far more complicated than most people realize and it takes into account a number of different factors, not just the number of correct answers. As such, you shouldn't be spending time trying to figure it all out - you'd be better served working on building up your skills. Also, since that algorithm is proprietary, no GMAT company has an exact match for it, thus CAT scores can vary a bit based on the 'biases' involved in their respective designs.
A far more useful gauge would be to review each CAT and determine how many questions you SHOULD have gotten correct, but didn't (due to a silly/little mistake). Those mistakes are the things that you have to fix to score at a higher level.
Have you taken any of the Official GMAC CATs yet? If so, then how did you score on those CATs?
GMAT assassins aren't born, they're made,
Rich