Ok, I've had the exact same problem as mention here while trying to install WP 1.2 Mingus today for two separate sites. I've gone through the recommended, but when I get to Step #4 (after hashing the pwd), I still can't log in. This is soooo frustrating, because I've had zero problems with WP until now.
Basically, the login page is being oddly redirected. Instead of going to:
It's going to:
I've tried registering as another user but the same thing still happens: back to the login page, without access. (Reporting a lost password doesn't work, either.)
I've even deleted the .htaccess file, to no avail.