Thanks for YAF.net, it's amazing.
I have some problems with moving the website and database to a new platform and doing the upgrade.
I did a NEW install on the new webserver, WS2012 with IIS7.5, and a WS2012 with SQL2012.
The new install worked fine.
Restored the old database and runned through the INSTALL.
Now the login doesn't work, it fails on bad password... But I checked the password by querying the usertable and used hashbytes to compare the hashed password, HASHBYTES('md5', 'MyPasswordWhatEver123!"#').
And it's equal...
Well, I'm a SQL guy and there might be some setting on the website I must adjust, I dunno...