Installing and upgrading help

This is a longshot but have you made sure that the moodle user has the correct permissions in the database?

See http://moodle.org/doc/?file=install.html#database for more info about this.

Also, if you can manually set the config setting for debug to be 7, that might help get some more errors printed to the screen.

I don't know about mysql, but in postgres you can have a db user owning both the database itself, or a table individually, I guess it's possible that you created the database to be owned by the wrong user, or with the wrong rights, or one table is wrong or something.