Problems after Beta 4 installation

[MarChelo]

Hi,
I´ve been running the SMF 2 Beta 3 and I decide to update the version to beta 4.
Following the instructions, I´ve downloaded the small package.

I do know If I did the right, but, I only uploaded the unzipped pack, and nothing more. I didn´t run anything. I was marked to delete the upgrade.php (I figured that it could be the reason of my problems), and I erased without run it at all.
The forum was working "fine". It says the new version, I re-installed some package that I used to had (Not to much, thank-o-matic and simple videos...). Everything seems to be ok.

After few hours, people start to complaint that they have problems for log in into the forum. And yes, is showed something like: "Data base error, please, advice to the administrator) -> me.

well... I´ve seek the solution in this forum, but I didn´t found anything, so, I uploaded the pack again, and this time, I ran the upgrade.php and everything were ok, until the end, where I can´t see my forum 

Can you help me please?
Thank you

[ccbtimewiz]

Do you have any errors in your Forum Error Log?

What modifications do you have installed?