well the only thing that could manage me to "fix" was to downgrade the iTunes to 11.0.2
but if you want to do what i did, you can even choose which version you want to downgrade, download the .dmg in this link>>> http://www.iphonefirmware.com/download-old-versions-of-itunes/
and almost following all steps from this link >> http://www.emacconsulting.com/apple/itunes/downgrade-itunes-11-to-itunes-10-7/
****here is what i did****
what i had to do was to download the app called Pacifist in this website , install, (since it is freeware, you will have to wait 15 seconds to click in the button, NOT YET listed in there ) choose the .dmg itunes from "open package button"
highlight "Contents of iTunes 11.0.2" (or the version of your choice) and click in the arrow upleft corner "Install"
when a popup box appears, you will be asked to enter your password credentials, and check to run as administrator, when other popups appears check the box "not show this again in this installation" and hit "Replace" and after hit "update" in the next one.
so after finishing, itunes wont open, you will have to create a new itunes library by openning itunes holding Option Key in your keyboard,
the new itunes folder will be create where had the last one before.
alright...
now you will have to enter in your old itunes folder and in "Open" all of your musics and apps (inside the iTunes media folder, and Mobile applications for apps)...easy way to do that is selecting all of them, and hit enter of simple click,
so it will be transfered to the "new" Itunes.
and that is it...
you now can enjoy itunes again without the password problem.
btw you will be promped with a popup of iTunes asking you if you want to update to iTunes 11.0.3, check "not to show this again" and hit the "not now" button.
best regards.